Which process demonstrates thermal energy transfer by radiation?
OA. Using a heated rock to warm a pet lizard
OB. Placing a pot of soup on a stove to heat the soup
OC. Adding warm air to a room at floor level to heat the room
OD. Using a heat lamp to keep food warm
4
SUBMIT

Answers

Answer 1

Answer: D. Using a heat lamp to keep food warm.

Explanation: Radiation is the transfer of heat energy through electromagnetic waves without the need for a medium.  In this process, heat energy is emitted in the form of electromagnetic waves and is absorbed by another object, causing an increase in its temperature.

Using a heat lamp to keep food warm involves the emission of infrared radiation.  The heat lamp produces electromagnetic waves in the form of infrared radiation, which are absorbed by the food, increasing its temperature and keeping it warm.  This process does not require direct contact or a medium for heat transfer.  Instead, the heat energy is transferred through the emission and absorption of electromagnetic waves, demonstrating thermal energy transfer by radiation.

Learn more about radiation here: https://brainly.com/question/31106159.


Related Questions

How many grams of solute are in the following solution?
250mL of 0.39M acetic acid, CH3CO2H

Answers

There are 5.85 grams of acetic acid (CH3CO2H) in the given solution.

To calculate the grams of solute in the given solution, we first need to calculate the number of moles of solute (acetic acid) present in the solution.

We know the volume of the solution (250 mL) and the molarity of the solution (0.39 M). We can use the following equation to calculate the number of moles of solute:

moles of solute = molarity × volume (in liters)

First, we need to convert the volume from milliliters to liters:

250 mL = 0.250 L

Now we can use the equation to calculate the number of moles of acetic acid:

moles of CH3CO2H = 0.39 M × 0.250 L = 0.0975 moles

Finally, we can use the molar mass of acetic acid to convert the number of moles to grams:

molar mass of CH3CO2H = 60.05 g/mol

grams of CH3CO2H = moles of CH3CO2H × molar mass of CH3CO2H

grams of CH3CO2H = 0.0975 moles × 60.05 g/mol = 5.85 g.

Learn more about acetic acid here:

https://brainly.com/question/15202177

#SPJ1

why doesn't catalyst shift the equilibrium position?

Answers

catalysts affect how fast reactions happen, not how much of the reactants are turned into products.

Answer:

catalysts do not shift the equilibrium position of a chemical reaction because they do not affect the free energy difference between reactants and products

Explanation:

To understand this better, let's consider an example. The Haber process is used to produce ammonia from nitrogen and hydrogen gas:

N2(g) + 3H2(g) ⇌ 2NH3(g)

This reaction is exothermic, meaning that it releases heat. According to Le Chatelier's principle, adding heat to an exothermic reaction will shift the equilibrium position towards the reactants (N2 and H2). Conversely, removing heat from the system will shift the equilibrium position towards the products (NH3).

Now, let's say we add a catalyst to this reaction. The catalyst will speed up both the forward and reverse reactions equally, without affecting their relative rates. This means that although the reaction will reach equilibrium faster with a catalyst present, it will still reach the same equilibrium position as it would without a catalyst.

For the equilibrium 2IBr(g)⇌I2(g)+Br2(g)
Kp=8.5×10−3 at 150 ∘C
If 2.9×10−2 atm of IBr is placed in a 2.0- L container, what is the partial pressure of IBr after equilibrium is reached?

Answers

The partial pressure of IBr after equilibrium is reached is:

P_IBr = 0.029 - x = 0.0265 atm.

What is Equilibrium?

In chemistry, equilibrium refers to a state in which the rates of the forward and reverse reactions are equal, resulting in a stable concentration of products and reactants. In other words, equilibrium occurs when the concentrations of reactants and products remain constant over time. The concept of equilibrium is important in many areas of chemistry, including chemical reactions, acid-base equilibria, and solubility equilibria.

We can start by setting up an ICE table:

2IBr(g) I2(g) Br2(g)

Initial 0.029 atm 0 atm 0 atm

Change -x +x +x

Equil. 0.029-x x x

The equilibrium constant expression for the reaction is:

Kp = (P_I2 * P_Br2) / P_IBr^2

At equilibrium, the partial pressures are:

P_I2 = P_Br2 = x

P_IBr = 0.029 - x

Substituting these expressions into the equilibrium constant expression gives:

8.5×10^-3 = (x * x) / (0.029 - x)^2

Solving for x gives:

x = 0.0025 atm

Learn more about Equilibrium from the given link

https://brainly.com/question/517289

#SPJ1

What is the gaseous state of a green bean casserole?​

Answers

Answer:

Green Bean Casserole is a classic.

The family recipe has passed down from one great-aunt to another.
Now it's causing gas and bloating across multiple generations of the family.

Explanation:

Consider the titration of 100.0 mL of 0.200 M acetic acid (Ka=1.8x10^-5) by 0.100 M KOH. Calculate the pH of the resulting solution after the following volumes of KOH have been added. a) 0.0 mL b) 50.0 mL c) 100.0 mL d) 110.0 mL e) 200.0 mL f) 260.0 mL

Answers

Explanation:

The titration of acetic acid with KOH is a weak acid-strong base titration. At the beginning of the titration (part a), we have only acetic acid in the solution, and its concentration is 0.200 M. As we add KOH, it reacts with acetic acid to form acetate and water:

CH3COOH + KOH → CH3COOK + H2O

The acetate ion is the conjugate base of acetic acid and can be considered a weak base. We can use the following equation to calculate the pH of the resulting solution at each point of the titration:

pH = pKa + log([A^-]/[HA])

where pKa is the acid dissociation constant of acetic acid (1.8 × 10^-5), [A^-] is the concentration of acetate ion, and [HA] is the concentration of undissociated acetic acid.

a) At the beginning of the titration (0.0 mL of KOH added), the solution contains only acetic acid. Therefore, [HA] = 0.200 M and [A^-] = 0 M.

pH = pKa + log([A^-]/[HA])

pH = -log(1.8 × 10^-5) + log(0/0.200)

pH = 2.40

The pH of the solution is 2.40.

b) When 50.0 mL of 0.100 M KOH is added, we have added 5.00 mmol of KOH. This amount of KOH reacts with 5.00 mmol of acetic acid, and the remaining 0.050 mol - 0.005 mol = 0.045 mol of acetic acid remains in the solution. At the same time, 0.005 mol of acetate ion is formed.

[HA] = 0.045 mol / 0.100 L = 0.450 M

[A^-] = 0.005 mol / 0.100 L = 0.050 M

pH = pKa + log([A^-]/[HA])

pH = -log(1.8 × 10^-5) + log(0.050/0.450)

pH = 4.41

The pH of the solution is 4.41.

c) When 100.0 mL of 0.100 M KOH is added, we have added 10.00 mmol of KOH. This amount of KOH reacts with 10.00 mmol of acetic acid, and there is no acetic acid remaining in the solution. At the same time, 0.010 mol of acetate ion is formed.

[HA] = 0 mol / 0.100 L = 0 M

[A^-] = 0.010 mol / 0.100 L = 0.100 M

pH = pKa + log([A^-]/[HA])

pH = -log(1.8 × 10^-5) + log(0.100/0)

pH = 4.74

The pH of the solution is 4.74.

d) When 110.0 mL of 0.100 M KOH is added, we have added 11.00 mmol of KOH. This amount of KOH reacts with 10.00 mmol of acetic acid, and there is an excess of 1.00 mmol of KOH in the solution. This excess KOH completely dissociates to give 1.00 mmol of OH^- ion. At

1. (a) Consider the following table .
which of the element :
a) is a halogen?
b) is most likely to be attracted by a magnet?
c) belongs to group I
d) would readily form an ion with a double negative charge?
e) what type of bond would exist between J and X when they combine?
f) how many neutrons are there in Q?
g) write the formula of the compound formed when R combines with X
h) state the element which exist as a diatomic molecule
I) select the element which belongs to the d- block of the periodic table
J) write the electronic configuration of the element Y​

Answers

Required Answer :

1. (a) Consider the following table .

which of the element :

a) is a halogen?

Ans. Element J is halogen.

b) is most likely to be attracted by a magnet?

Ans. Element Y is most likely to be attracted by a magnet.

c) belongs to group I.

Ans. Element X belongs to group 1.

d) would readily form an ion with a double negative charge?

Ans. Element R would readily form an ion with a double negative charge.

e) what type of bond would exist between J and X when they combine?

Ans. Ionic bond would exist between J and X when they combine.

f) how many neutrons are there in Q?

Ans. Atomic number of Q = 13

Mass Number = 27.

Number of neutrons = Mass Number - Atomic number

Number of neutrons = 27 - 13.

Hence, There are 14 neutrons in Element Q.

g) write the formula of the compound formed when R combines with X.

Ans. When R combines with X it forms X₂R.

h) state the element which exist as a diatomic molecule

Ans. Element J exist as a diatomic molecule.

I) select the element which belongs to the d- block of the periodic table

Ans. Element Y belongs to the d- block of the periodic table.

J) write the electronic configuration of the element Y

Ans. Electronic configuration of the element Y is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵ or [Ar] 4s¹ 3d⁵.

A supply of NaOH is known to contain the contaminants NaCl and MgCl₂. A 4.955 g sample of this material is dissolved and diluted to 500.00 mL with water. A 20.00 mL sample of this solution is titrated with 22.26 mL of a 0.1989 M solution of HCI. What percentage of the original sample is NaOH? Assume that none of the contaminants react with HCI.​

Answers

Answer:

88.55%

Explanation:
4.9995 g of crude material contain 4.4275 g of NaOH, therefore  

4.4275/4.9995 = 88.55%

why is atomic emission more sensitive to flame instability than atomic absorption ?

Answers

Answer:

Atomic emission is more sensitive to flame instability than atomic absorption because during atomic emission, the intensity of the emitted light is proportional to the concentration of the element being measured. If the flame is unstable, it can cause fluctuations in the intensity of the light being emitted, which can lead to errors in the measurement of the element's concentration. In contrast, in atomic absorption, the intensity of the absorbed light is measured, which is less sensitive to flame instability since the amount of light absorbed by the element is proportional to its concentration regardless of the flame's stability.

Answer:

Atomic emission is more sensitive to flame instability than atomic absorption because atomic emission is based on the analysis of light emitted from excited atoms in the flame. In contrast, atomic absorption is based on light absorption by the flame's particles.

Flame instability can lead to changes in the temperature and pressure of the flame, which can affect the excited states of the atoms in the flame. When the flame is unstable, it can cause fluctuations in the number of excited atoms and the length of time they stay excited. This, in turn, can lead to fluctuations in the amount of light emitted by the excited atoms, making it more difficult to accurately measure the analyte concentrations in the sample using atomic emission spectroscopy.

On the other hand, atomic absorption spectroscopy is less sensitive to flame instability because the light absorption by the atoms in the flame is not as dependent on the excitation states of the atoms. The atoms in the flame absorb light at specific wavelengths regardless of their excited states. Hence, fluctuations in the excited state populations have less of an impact on the absorption signal. However, atomic absorption spectroscopy can still be affected by other factors, such as changes in the temperature and pressure of the flame and the presence of other interfering species in the sample.

Calculate the Kelvin temperature to which 21.0 L of a gas at 34°C would have to be heated to change the volume to 41.0 L. The pressure and number of particles remain constant.

Answers

In order to convert the volume from 21.0 L to 41.0 L while maintaining the same pressure and particle number, the gas would need to be heated to a temperature of 580.49 K.

When the amount of moles and pressure are both constant?

According to Boyle's law, the pressure and volume of a gas follow an inverse relationship when the gas's temperature and molecular composition are both constant.

This problem can be solved using the coupled gas law, which connects a gas's pressure, volume, and temperature:

(P1 V1) / T1 = (P2 V2) / T2

In this problem, we are given P1 = P2, V1 = 21.0 L, V2 = 41.0 L, and            T1 = 34°C. We want to find T2 in Kelvin.

First, we need to convert T1 from Celsius to Kelvin:

T1 = 34°C + 273.15

T1 = 307.15 K

Next, we can rearrange the combined gas law to solve for T2:

T2 = (P2 V2 T1) / (P1 V1)

Substituting the given values, we get:

T2 = (1 atm * 41.0 L * 307.15 K) / (1 atm * 21.0 L)

T2 = 580.49 K

To know more about gas law visit:-

https://brainly.com/question/24519415

#SPJ1

2. Which chemical below is easier to dissolve in water
a) KBr b) CO2 c)CH4
d) O2

Answers

The correct answer is a) KBr.

KBr is an ionic compound composed of a metal (K) and a non-metal (Br). When this compound is added to water, the polar water molecules surround the ions in the solid and separate them, which leads to the compound dissolving in water.

What is Ionic Compound?

An ionic compound is a chemical compound composed of ions held together by electrostatic forces called ionic bonds. Ions are atoms or molecules that have gained or lost one or more electrons, giving them a positive or negative charge. In an ionic compound, a positively charged ion (cation) and a negatively charged ion (anion) are attracted to each other to form a stable compound.

CO2, CH4, and O2 are nonpolar molecules, and therefore, do not dissolve well in water. CO2 and O2 are gases at room temperature and pressure, while CH4 is a gas at room temperature but can be liquefied under pressure.

Learn more about Ionic Compound from the given link

https://brainly.com/question/2687188

#SPJ1

The compound lead(II) acetate is a strong electrolyte. Write the reaction when solid copper (II) acetate is put into water

Answers

Copper ions  and acetate ions make up the chemical known as solid copper (II) acetate . It will dissolve and split into its component ions when placed in water. Moreover, copper (II) acetate is a strong electrolyte, which means that when dissolved in water, it almost entirely separates into ions.

What happens when solid lead II acetate is dissolved in water?

Pb(OAc) 23H₂O, a colorless or white efflorescent monoclinic crystalline material, is the trihydrate that is created when it reacts with water.

Copper II acetate is either liquid or solid ?

Cu₂(OAc)4(H₂O) is a more bluish-green crystalline solid than anhydrous copper(II) acetate. Copper acetates have been utilized as fungicides and green pigments in some way since antiquity. Copper acetates are currently utilized as reagents for  the synthesis of various inorganic and organic compounds.

To know more about compound  visit:-

brainly.com/question/13516179

#SPJ9

Helpppp

describe an incident that shows how you were doing "selection" during the process of perception. Then, give your own example about a stereotype that you do.

Answers

Selection is the process by which we filter out irrelevant information and focus on the information that is most relevant to us.

What are the examples of selection process?

For example, when we walk down a busy street, we may not pay attention to every detail of every building or person we pass by. Instead, we might focus on things that stand out, such as a bright billboard or an interesting conversation nearby.

Regarding stereotypes, one common example is the belief that all individuals from a certain race, gender, or religion share certain characteristics or behaviors. This stereotype is often based on limited or inaccurate information and can lead to biased judgments and discrimination. It's essential to recognize and challenge our own stereotypes to avoid unfairly treating others based on their group membership.

Learn more about selection here: https://brainly.com/question/14874301

#SPJ1

Magnesium hydroxide neutralizes stomach acid (primarily hydrochloric acid). How much hydrochloric acid, in g, would be neutralized by 5.50g magnesium hydroxide?


______ g hydrochloric acid would be neutralized.

Answers

6.86 g of hydrochloric acid would be neutralized by 5.50 g of magnesium hydroxide.

The balanced chemical equation for the reaction between magnesium hydroxide and hydrochloric acid is:

Mg(OH)₂(s) + 2HCl(aq) → MgCl₂(aq) + 2H₂O(l)

From the equation, we can see that 1 mole of Mg(OH)₂ reacts with 2 moles of HCl. We can use the molar mass of Mg(OH)₂ to convert its mass to moles:

moles of Mg(OH)₂ = mass / molar mass = 5.50 g / 58.32 g/mol = 0.0942 mol

Since 1 mole of Mg(OH)₂ reacts with 2 moles of HCl, we know that twice as many moles of HCl will be neutralized:

moles of HCl neutralized = 2 × moles of Mg(OH)₂ = 2 × 0.0942 mol = 0.1884 mol

Finally, we can use the molar mass of HCl to convert the moles of HCl to grams:

mass of HCl neutralized = moles of HCl × molar mass = 0.1884 mol × 36.46 g/mol = 6.86 g

Therefore, 6.86 g of hydrochloric acid would be neutralized by 5.50 g of magnesium hydroxide.

learn more about neutralization here

https://brainly.com/question/23008798

#SPJ1

What is the volume of a 0.5 M solution of HCl if it contains 36.5 grams of solute?

Molar mass (H -1 g/mol)(Cl - 35.5 g/mol)

___ L (Answer Format: X)

Answers

Answer: 2 L or 2000 mL

Explanation:

A 1 molar (1 M) solution is equal to 1 mole of the solute dissolved in 1 L of solution.

For HCl (mw 36.5) 1 mole = 36.5 g

1 molar (1 M) = 1 mole/1 liter (or 36.5 g/L)

So

0,5 M = 1 mole/x

(x is the volume we are solving for)

Multiply both sides by x and you get

0.5x=1

Now multiple both sides by 2

X=2

So it’s 2L volume

Give the IUPAC name for: image attached ​

Answers

The IUPAC name of the given compound is 1-bromo-3-ethylpentane.

What are the steps involved in writing IUPAC name?

IUPAC (International Union of Pure and Applied Chemistry) naming is a system used to give standardized names to chemical compounds. The steps involved in doing IUPAC naming are as follows:

1. Identify the longest carbon chain: The parent chain is the longest continuous chain of carbon atoms in the molecule.

2. Number the carbon atoms: The carbon atoms in the parent chain are numbered starting from the end nearest to the substituent, and the substituents are given numbers based on the carbon to which they are attached.

3. Identify and name the substituents: Substituents are groups of atoms that replace hydrogen atoms on the parent chain. They are named according to their functional groups.

4. Write the name: The name of the compound is written by listing the names of the substituents in alphabetical order, along with their position on the parent chain.

5. Add prefixes and suffixes: Prefixes are added to indicate the number of substituents on the parent chain, and suffixes are added to indicate the functional group present.

6. Check the name: The final step is to check the name for accuracy and consistency with IUPAC rules.

It's important to note that the naming of complex organic compounds can involve additional rules and naming conventions beyond these basic steps.

Learn more about carbon here:

https://brainly.com/question/22530423

#SPJ9

Part A
Identify the problem that the cold pack must address.

Answers

The cold pack is designed to address the problem of pain and swelling due to injury or inflammation.

What is cold pack?

A cold pack, also known as a cold compress, is a medical device designed to provide cold therapy to a specific area of the body. It typically consists of a gel-filled plastic bag or pouch that is placed in the freezer for a period of time to lower its temperature.

When applied to the affected area, the cold temperature helps to reduce blood flow, which in turn reduces inflammation, swelling, and pain. Cold packs are commonly used to treat minor injuries such as sprains, strains, and bruises, as well as to alleviate pain and swelling associated with chronic conditions like arthritis.

Learn about cold pack here https://brainly.com/question/7745193

#SPJ1

Acetylene (C₂H₂) gas is often used in welding torches because of the very high heat produced when it reacts with oxygen (O₂) gas, producing carbon dioxide
gas and water vapor. Calculate the moles of water produced by the reaction of 2.2 mol of acetylene. Be sure your answer has a unit symbol, if necessary, and
round it to the correct number of significant figures

Answers

Answer: 2.2 moles

Explanation:

To calculate the moles of water produced, we first need to write down the balanced chemical equation for the combustion of acetylene:

C₂H₂(g) + O₂(g) → CO₂(g) + H₂O(g)

To balance the equation, we need to make sure that there are the same number of atoms for each element on both sides of the equation. The balanced equation is:

2C₂H₂(g) + 5O₂(g) → 4CO₂(g) + 2H₂O(g)

Now we can use stoichiometry to find the moles of water produced:

2.2 mol C₂H₂ * (2 mol H₂O / 2 mol C₂H₂) = 2.2 mol H₂O

So, 2.2 moles of acetylene will produce 2.2 moles of water when reacted with a sufficient amount of oxygen.

A piston–cylinder device initially contains 0.33-kg steam at 3.5 MPa, superheated by 107.4oC. Now the steam loses heat to the surroundings and the piston moves down, hitting a set of stops at which point the cylinder contains saturated liquid water. The cooling continues until the cylinder contains water at 200oC. What is the amount of heat transfer when the piston first hits the stops and the total heat transfer

Answers

Both the initial heat transfer when the piston initially contacts the stops and the overall heat transfer throughout the procedure are -11,172 kJ.

How do you figure out how much heat is transferred overall and when the piston first strikes the stops?

h1 = 3279.1 kJ/kg

h2 = 751.6 kJ/kg

Q = ΔU = m(u2 - u1) (u2 - u1)

where m is the steam's mass.

We may use the ideal gas law to determine the mass of the steam:

PV = mRT

PV/(RT) = (3.5 MPa) (0.33 m3)/(0.287 kJ/kg-K) (380.4 K) = 4.47 kg for the formula m.

We can now determine the rate of heat transfer:

Q is equal to m(u2 - u1) = (4.47 kg)(751.6 kJ/kg - 3279.1 kJ/kg) = -11,172 kJ

Heat is leaving the system, as indicated by the negative sign.

To learn more about piston-cylinder device visit:

brainly.com/question/22969319

#SPJ9

Acetic acid has a molar mass of 60.05 g/mol. If 16.84 grams of acetic acid are present, how many moles of acetic acid does that correspond t

Answers

The number of moles of acetic acid which has a molar mass of 60.05 g/mol present in 16.84 grams of acetic acid is 3.56.

Given the molar mass of Acetic acid (M) = 60.05 g/mol.

The mass of acetic acid (m) = 16.84g

Let the number of moles = n

A mole is a unit of measurement used in chemistry to measure amount of substance. It is calculated as molar mass by mass of the given substance. The mole is defined as the amount of a substance that contains as many elementary entities (atoms, molecules, ions, etc.) as there are atoms in exactly 12 grams of carbon-12. One mole of a substance contains this number of particles, and can be used to calculate the mass of a given sample of the substance.

n = 60.05/16.84 = 3.56 moles

Hence the required number of moles are 3.56.

To learn more about molar mass click here https://brainly.com/question/12127540

#SPJ1

A student removes H⁺ ions from the reaction shown. Will the solution turn more green or more purple?

A: More purple
B: More green
C Changing the H+ ion won't affect the equilibrium

Answers

Answer:More purple

Explanation: Its more purple

Calculate the mass of chlorine in 25 kg of CFCl3.
Can someone explain the steps please thanks

Answers

The mass of chlorine in 25kg of [tex]CFCl_3[/tex] is 6,435g where mass is a measure of the amount of matter in an object. It is measured in kilograms (kg) or grams (g).

The mass of [tex]CFCl_3[/tex] = 25kg

The molecular weight of [tex]CFCl_3[/tex] (also known as Freon-11) is = 137.37 g/mol.

It means one mole of [tex]CFCl_3[/tex] = 137.37 g.

Since chlorine is an element, one mole of chlorine is equal to its atomic weight, which is 35.45 g/mol.

Therefore, number of moles 25 kg of [tex]CFCl_3[/tex] contains =

(25 kg) / (137.37 g/mol) = 182.4 mol of [tex]CFCl_3[/tex].

To calculate the mass of chlorine in 25 kg of [tex]CFCl_3[/tex], we need to multiply the number of moles of chlorine by its atomic weight.

The mass of chlorine in 25 kg of [tex]CFCl_3[/tex] is = 182.4 mol * 35.45 g/mol = 6,435 g of chlorine.

Hence, the mass of chlorine in 25 kg of [tex]CFCl_3[/tex] is 6,435 g.

To learn more about mass click here https://brainly.com/question/11622869

#SPJ1

What volume would a 1.75 mole sample of O2 gas occupy, if it had a pressure of 2.7 atm, and a temperature of 35 °C?

Answers

Answer:

9 ans

Explanation:

cold 20 -11 =9 ans

summer 20-11=9 ans

Please solve whichever you can PICTURE INCLUDED! show work pls

Answers

The molar entropy from the question that we have here is 85.1kJ/K.mol as shown.

What is the molar entropy?

The molar entropy of a substance can be calculated by dividing the total entropy of the substance by the number of moles present. The entropy of a substance can be determined experimentally by measuring its heat capacity or by analyzing its thermodynamic behavior under different conditions.

We know that;

Entropy = ΔH/T

= 1.6 * 10^4 * 10^3J/mol/187.95 K

= 85.1kJ/K.mol

For the bromide ion;

Rate = 5/1 * 2.7 * 10^-3 mol/s

= 1.35 * 10^-2 mol/s

Learn more about entropy:https://brainly.com/question/13135498

#SPJ1

What is the blood alcohol level in mass percent if 8.33 mL of 0.04988 M K2Cr2O7 is required for titration of a 9.9950 g sample of blood?

Answers

The blood alcohol level in mass percent is 0.0956% if 8.33 mL of 0.04988 M [tex]K2Cr2O7[/tex] is required for titration of a 9.9950 g sample of blood.

To calculate the blood alcohol level in mass percent, we need to first determine the amount of ethanol present in the blood sample. This can be done by using a redox titration with potassium dichromate [tex](K2Cr2O7)[/tex], which oxidizes the ethanol to acetic acid.

The balanced chemical equation for the reaction is:

[tex]C2H5OH + 2Cr2O7^2- + 16H+ → 2CO2 + 4Cr^3+ + 11H2O[/tex]

From the balanced equation, we can see that the stoichiometric ratio between [tex]K2Cr2O7[/tex] and ethanol is 2:1. Therefore, the moles of ethanol in the blood sample can be calculated as:

moles of ethanol = 0.5 × moles of [tex]K2Cr2O7[/tex]

The moles of [tex]K2Cr2O7[/tex]can be determined from its concentration and volume used in the titration:

[tex]moles of K2Cr2O7 = 0.04988 mol/L × 8.33 × 10^-3 L = 4.15 × 10^-4 mol[/tex]

Substituting this value into the equation above, we get:

moles of ethanol = 0.5 × 4.15 × 10^-4 mol = 2.075 × 10^-4 mol

The mass of ethanol in the blood sample can be calculated from its molar mass:

[tex]mass of ethanol = 2.075 × 10^-4 mol × 46.07 g/mol = 9.551 × 10^-3 g[/tex]

Finally, the blood alcohol level in mass percent can be titration calculated as:

mass percent = mass of ethanol / mass of blood sample × 100%

mass percent = [tex]9.551 × 10^-3 g / 9.9950 g × 100%[/tex]

mass percent = 0.0956%

Therefore, the blood alcohol level in mass percent is 0.0956%.

Learn more about titration here

https://brainly.com/question/31229711

#SPJ1

A 1.50-L bulb containing Ne at 470 torr is connected by a valve to a 2.50-L bulb containing CF4 at 110 torr. The valve between the two bulbs is opened and the two gases mix. The initial gas pressures as known to three significant figures.

(a) What is the partial pressure (torr) of Ne?
(b) What is the partial pressure (torr) of CF4?
(c) What is the total pressure?
(d) What is the mole fraction of Ne?

Answers

(a) Partial pressure of Ne is 470 torr. (b) Partial pressure of of CF₄ is 110 torr. (c) Total pressure is 580 torr. (d) Mole fraction of Ne is 0.621.

(a) The initial pressure of Ne is 470 torr, so the partial pressure of Ne after mixing is also 470 torr.

(b) The initial pressure of CF₄ is 110 torr, so the partial pressure of CF₄ after mixing is also 110 torr.

(c) The total pressure is the sum of the partial pressures of the two gases:

Total pressure = partial pressure of Ne + partial pressure of CF₄

Total pressure = 470 torr + 110 torr

Total pressure = 580 torr

(d) To find the mole fraction of Ne, we need to know the number of moles of Ne and CF₄. We can use the ideal gas law to find the number of moles of each gas:

PV = nRT

n = PV/RT

For Ne:

n = (470 torr x 1.50 L)/(0.0821 L·atm/mol·K x 298 K)

n = 19.25 mol

For CF₄:

n = (110 torr x 2.50 L)/(0.0821 L·atm/mol·K x 298 K)

n = 11.72 mol

The total number of moles is:

nTotal = nNe + nCF₄

nTotal = 19.25 mol + 11.72 mol

nTotal = 30.97 mol

The mole fraction of Ne is:

XNe = nNe/nTotal

XNe = 19.25 mol/30.97 mol

XNe = 0.621

Therefore, the mole fraction of Ne is 0.621.

To know more about partial pressure please refer: https://brainly.com/question/16749630

#SPJ1

Please solve whichever you can PICTURE INCLUDED! show work pls

Answers

As may be shown, the molar entropy from the question is 85.1 kJ/K.mol.

What does molar entropy mean?

By dividing the substance's overall entropy by the quantity of moles present, one can determine a substance's molar entropy. By measuring a substance's heat capacity or by examining its thermodynamic behavior under various circumstances, one can empirically ascertain the entropy of that substance.

Entropy = ΔH/T

= 1.6 * 10^4 * 10^3J/mol/187.95 K= 85.1kJ/K.mol

b) If we have the Br- ion;

Rate = 5/1 * 2.7 * 10^-3 mol/s

= 1.35 * 10^-2 mol/s

Learn more about entropy:brainly.com/question/13135498

#SPJ1

please solve them for me thank you

Answers

Carolyn's observations suggest that the Elodea plant produced significantly more bubbles in the sunlit window than it did on her desk. This is likely because Elodea, like all plants, undergoes photosynthesis, a process in which they use sunlight to convert carbon dioxide and water into glucose and oxygen.

The oxygen produced during photosynthesis is released into the water as bubbles, which is what Carolyn observed.

What is the observation about?

When the Elodea was on Carolyn's desk, it may not have been receiving enough light to undergo photosynthesis at its maximum capacity, resulting in fewer bubbles being produced.

However, when Carolyn moved the aquarium to a sunlit window, the Elodea likely received more light, allowing it to undergo photosynthesis more efficiently, resulting in a higher number of bubbles being produced.

Overall, Carolyn's observations demonstrate the importance of light for plants to undergo photosynthesis and produce oxygen.

Learn more about observations on

https://brainly.com/question/2419635

#SPJ1

How much heat has to be added to 235 g of iron at 25.0°c to raise the temperature of the iron to 250.0°c?

Answers

Answer:

23205 J or 2.37 × 10⁴ J or 23.7 kJ

Explanation:

The amount of heat required to change the temperature of a substance can be calculated using the formula: q = mcΔT, where q is the heat added, m is the mass of the substance, c is its specific heat capacity, and ΔT is the change in temperature.

The specific heat capacity of iron is 0.44 J/g K1. So, to raise the temperature of 235 g of iron from 25.0°C to 250.0°C (a change of 225°C), you would need to add:

q = (235 g) × (0.44 J/g K) × (225 K) = 23205 J

So you would need to add 23205 joules of heat to raise the temperature of 235 g of iron from 25.0°C to 250.0°C.

What is the final temperature of a sample of ammonia gas if the sample went from a volume of 250mL, a pressure of 3.84 atm, and 35 degrees celsius to a pressure of 5.84 atm and a volume of 215 mL?

T2 = ___ K (Answer Format: XXX.X)

Combined gas law

Answers

A sample of ammonia gas has a final temperature of 313.25K.

The Combined Gas Law is a combination of the Ideal Gas Law and Charles’s Law. It states that the ratio of the pressure of a gas, its volume, and its temperature is constant, provided the amount of gas and the molar mass of the gas remain the same. The combined gas law states that the ratio of the product of pressure and volume of a gas is equal to the product of the pressure and volume of the same gas at a different temperature.

Rearranging the equation to solve for T2, we have:

[tex]T2 = \frac{(P1V1T1)}{P2V2}[/tex]

Substituting the given values, P1 has value 3.84 atm,V1 has value 250mL,P2 has value 5.84 atm,V2 has value 215mL and T1 has value (35+273) degrees, we have:

[tex]T2 = \frac{(3.84 * 250 * 35 + 273) }{ (5.84 * 215)}\\T2 = 313.25 K[/tex]

Therefore,The final temperature of a sample of ammonia gas is 313.25K

learn more about Combined Gas Law Refer:brainly.com/question/30458409

#SPJ1

plssss i need this immediately

Answers

The heat that is going to be released in the reaction can be obtained as 930.3 kJ.

What is the heat of reaction?

The heat of reaction, also known as the enthalpy change of a reaction, is the amount of heat energy that is released or absorbed during a chemical reaction. It is denoted by the symbol ΔH and has units of joules per mole (J/mol) or kilojoules per mole (kJ/mol).

Number of moles of butane = 41.06g/58 g/mol = 0.7 moles

If 2 mole release 2658 kJ

0.7 moles will release 0.7 * 2658/2

= 930.3 kJ

Learn more about heat of reaction:https://brainly.com/question/30464598

#SPJ1

Other Questions
predict how changing the partial pressure of carbon dioxide will affect the ph and concentration of bicarbonate ions in the plasma please help 15 pointsThe numbers in this chart represent the number of minutes a group of five high school students spent talking on their cell phones one day.Which of the following statements is true about this data? A. The data set has two modes. B. The data set has no mean. C. The median is 41. D. The mode and median are equal. The buying rate and selling rate of Australian dollar in a bank are Rs.132 and Rs 132.85 respectively.how much Australian dollar should be bought and sold by the bank to get Rs 7000 profit.find it. a woman borrows money from a bank to purchase a house. she promises to give the bank the house if she cannot repay the loan. this woman has signed a . 1. Swimming in the shallow water was a ______________ of herring.2. A ___________ of sheep was happily grazing in the field.3. All night we could hear the _____________ of wolves howling.. a rectangular garden of area 75 square feet is to be surrounded on three sides by a brick wall costing $10 per foot and on one side by a fence costing $5 per foot. find the dimensions of the garden that minimize the cost of materials. which parameter determines the location of the alert log? a. core dump dest b. background dump dest c. alert log dest d. diagnostic dest what traditional strategy does freddie mac use to help create liquidity in mortgage markets? issuing bonds and using the proceeds to purchase high-quality mortgages on the primary mortgage market issuing bonds and using the proceeds to purchase very risky subprime mortgages on the primary mortgage market issuing bonds and using the proceeds to purchase very risky subprime mortgages on the secondary mortgage market issuing bonds and using the proceeds to purchase high-quality mortgages on the secondary mortgage market multiple choice question sonja was not promoted to the position of manager of the road work crew because her boss doesn't feel that a woman can supervise as well as a man. this an an example of . really fast delivery services has the collected the following information about operating expenditures for its delivery truck fleet for the past five years: year miles operating costs 2013 55,000 $195,000 2014 70,000 $210,000 2015 50,000 $180,000 2016 65,000 $205,000 2017 85,000 $225,150 using the high-low method, what is the cost estimate for variable costs for 2018? the balance in accounts receivable at the beginning of 2021 was $690. during 2021, $2,400 of credit sales were recorded. if the ending balance in accounts receivable was $210 and $100 in accounts receivable were written off during the year, the amount of cash collected from customers during 2021 was: according to robert merton, members of revolutionary political organizations such as the irish republican army would typically be classified as a 1 kg metal cube at 200 degrees celsius is added to a beaker with 1 kg of very 10 degree celsius water. the metal cools off, while the water warms up. what is the approximate temperature when they reach equilibrium. if stock a has a beta of 1 and stock b has a beta of 1.5, which of the following is most likely to be true? group of answer choices the required return for stock b will be 50% higher than the required return for stock a. the risk premium for stock b will be 50% higher that the risk premium for stock a, but the same riskless interest rate would apply when we determine the fair rate of return for each stock. stock a must have higher unique risk than stock b. stock b must have higher unique risk than stock a. how many degrees is a obtuce angel Translate the verbal phrase into a mathematical expression. Use x to represent the unknown number.the product of 6 less than a number and 2 more than the numberThe complete verbal phrase translates to (Do not perform the calculation.) starting from very far away, an object is moved closer and closer to a diverging lens, eventually reaching the lens. what happens to its image? (there could be more than one correct choice.) a) the image gets closer and closer to the lens. b) the image gets farther and farther from the lens. c) the image always remains virtual. d) the image eventually changes from real to virtual. e) the image keeps getting larger and larger. businesses adopting different generic strategies question 1 options: may comprise an industry. comprise a strategic group. always compete for different customers. none of the above. Pls help, Micheal tracked the value of his boat each year after he purchased it. Determine whether the data are linear, quadratic, or exponential. Use regression to the function that models the data. Please help ASAPIn academic essays, signal phrases include an author's name, source, or title only appear at the end of a sentence risk plagiarism by not crediting a source transition from one paragraph to the next