Answer:
The bracelet is made of gold.
Explanation:
The bracelet displaces the water by [tex]11.7cm^3-9.2cm^3 = 2.5cm^3[/tex] and thus has a volume of [tex]2.5cm^3[/tex]. If the bracelet has a mass of 45g, we know that the density of the bracelet is then [tex]\frac{45g}{2.5cm^3}[/tex], which can be simplified to [tex]18\frac{g}{cm^3}[/tex]. This is closer to the density of gold, so it can be assumed that the bracelet is made of gold.
Which of these steps in the rock cycle occurs only in the formation of metamorphic rock.
a erosion
b compaction
c cementation
d recyrstallization
HELP ME PLEASE!!! WILL MARK BRAINLIEST!!
Answer:
See answers below
Explanation:
-44.3 kj/mole * x moles = - 18.7 kj
solve for x = .422 mole dissolved
Mole weight of NaOH is
Na = 22.989 O = 15.999 H = 1.008 gm/mole
= ~~ 40 gm/mole for NaOH
40 gm / mole * .422 mole = 16.88 gm of NaOH
Which factor varies between the isotopes of an element?.
Answer:
neutron number
Explanation:
^
which will get spoiled faster: plum in water or plum in the open?
Answer:
It depends
(plum will spoil more quickly at warm temperatures)
Explanation:
A chemical buffer is a solution that increases pH changes when small quantities of an acid or base are added. True False
Answer:
false
Explanation:
A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is added to it. A buffer protects from ph increasing.
Chemical buffers are substances that are necessary to preserve the constancy of pH in various biological and chemical systems. Therefore, the given statement is True.
They are composed of either a weak base and its conjugate acid, or vice versa. The weak base component of the buffer reacts with the acid upon addition, reducing the pH rise. Similarly, when a base is added, the weak acid component of the buffer reacts with it to prevent the pH from falling significantly.
This ability to withstand pH variations is essential for preserving the proper operation of biological systems, such as blood pH in the human body, as well as in other laboratory and industrial operations where it is necessary to preserve a stable pH for best results.
Therefore, the given statement is True.
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Which reaction would cause a decrease in entropy?
A. 2NOCI(9) + 2NO(g) + Cl2(9)
B. 2NH3(9) ► N2(g) + 3H2(9)
C. 2CC14(9) + O2(g) → 2C0C12(g) + 2Cl2(9)
D. CO(g) + 3H2(g) → CH4(9) + H20(9)
2NOCI(9) + 2NO(g) + Cl2(9) shows decrease in entropy.
What is Entropy?Entropy in thermodynamic refers to the degrees that represent the absence of system's thermal energy that is not available to perform mechanical work, which is the degree of disorder or randomness in the system.
Therefore, 2NOCI(9) + 2NO(g) + Cl2(9) shows ddecrease in entropy because it shows degree of disorderliness is low
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True or false The reaction is fastest when few bubbles are being produced.
Answer:
no, it is fastest when many bubbles are produced.
Explanation:
Scientists used to believe that chemical reactions fueled the sun. Why did this lead them to believe that the sun was very young? What kind of reactions do we now think are responsible for the energy released by the sun? In one to two sentences , explain your reasoning 2 points )
The energy produced by the sun is as a result of nuclear reactions which produces large amounts of energy.
What are chemical reactions?Chemical reactions are reactions which occur as a result of a rearrangement of atoms of elements to form new combinations of substances known as compounds.
Since chemical reactions which have relatively short lifespans, scientist would have assumed that the sun is very young.
However, nuclear reactions have been proven to be the means by which the sun produces its energy.
Nuclear reactions release large amounts of energy and have relatively long lifespans.
Therefore, the energy produced by the sun is as a result of nuclear reactions.
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Simple question.
Why do tsunamis do most of their damage onshore, and not in the middle of the ocean?
Answer:
im assuming its due to something like water on water not eing as bad as the thwap of water on land. this wasnt a test question was it?
Explanation:
Answer:
As the tsunami waves become compressed near the coast, the wavelength is shortened and the wave energy is directed upward - thus increasing their heights considerably. Just as with ordinary surf, the energy of the tsunami waves must be contained in a smaller volume of water, so the waves grow in height. and they can't do damage out in the middle of the ocean because there is not much to damage out in sea
Explanation:
What is the percent yield when a reaction vessel that initially contains 68.0 kg CH4 and excess steam yields 16.9 kg H2
When a reaction vessel initially containing 68.0 kg [tex]CH_4[/tex] and excess steam yields 16.9 kg [tex]H_2[/tex], the percent yield would be 49.8%
Percent yieldRecall that: percent yield = yield/theoretical yield x 100%
From the equation of the reaction:
[tex]CH_4 + 2H_2O --- > CO_2 + 4H_2[/tex]
The mole ratio of methane to steam is 1:4.
Mole of 68.0 kg methane = 68000/16.0 = 44239.4 moles
Equivalent mole of [tex]H_2[/tex]= 16,957.6 moles
Mass of 16,957.6 moles [tex]H_2[/tex] = 16,957.6 x 2 = 33,915.2 grams or 33.92 kg
Percent yield = 16.9/33.92 x 100% = 49.8%
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The percentage yield of the reaction that yields 16.9 kilograms of Hydrogen gas, H₂ is 66.3%
Balanced equationCH₄ + H₂O —> CO + 3H₂
Molar mass of CH₄ = 16 g/mol
Mass of CH₄ from the balanced equation = 1 × 16 = 16 g = 0.016 Kg
Molar mass of H₂ = 2 g/mol
Mass of H₂ from the balanced equation = 3 × 2 = 6 g = 0.006 Kg
SUMMARY
From the balanced equation above,
0.016 Kg of CH₄ reacted to produce 0.006 Kg of H₂
How to determine the theoretical yield of H₂From the balanced equation above,
0.016 Kg of CH₄ reacted to produce 0.006 Kg of H₂
Therefore,
68 Kg of CH₄ will react to produce = (68 × 0.006) / 0.016 = 25.5 Kg of H₂
How to determine the percentage yield Actual yield of H₂ = 16.9 KgTheoretical yield of H₂ = 25.5 KgPercentage yield =?Percentage yield = (Actual / Theoretical) × 100
Percentage yield = (16.9 / 25.5) ×100
Percentage yield = 66.3%
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Determine the volume of a balloon at STP assuming that it occupies a volume of 7.75 L at a temperature of 0ºC and a pressure of 125 kPa.
Answer:
v2 = 9.69L
Explanation:
p1 v1/t1 = p2 v2/t2
P = Pressure
V = Volume
T = Temperature
T = 273k
P = 1 atm
1.23 x 7.75/273k = 1xv2/273
The slashes I used represent as fractions. (:
how do i solve this?
Answer:
57.6g
Explanation:
In the balanced equation H2O and Mg(OH)2 have the same coefficient (1) so we know that 3.2 moles of H2O react to form 3.2 moles of Mg(OH)2. Now we just have to calculate the mass of the H2O which we can do by finding the molar mass from the periodic table. For this just add the molar masses of the consituent atoms. (2(1)+1(16))=18g/mol H2O. Now that we know the molar mass we just have to multiply it by the amount of moles. 18*3.2=57.6g H2O
Scenario
HURRY I NEED HELP ASAP
A student masses 40 g copper (11) oxide Cuo, a black solid, and heats the substance using a Bunsen burner until the sample turns a reddish color. The chemical equation for the reaction issiven below. According to the reaction, the copper (1) oxide decomposes to produce copper(1) oxide and oxygen
4CuO → 2Cu2O + O2
Black solid Red solid Colorless gas
40 g. ? g
? g
Based on the evidence, write a scientific explanation describing the exact mass of the copper() oxide produced Provide mathematical evidence and give your reasoning in a way that demonstrates your understanding of the scientific principles involved.
72 g of Copper(i) oxide will be produced by 40 g of CuO base on the law of conservation of mass.
What mass of copper (i) oxide is produced?The law of conservation of mass states that mass remains constant at the end of every reaction.
The equation of the reaction is given below:
[tex]4CuO → 2Cu_2O + O_2[/tex]
Based on the equation of reaction, 4 moles of copper (ii) oxide produces 2 moles of copper (i) oxide.
Mass of 4 moles of CuO = 4 × 80 = 160 g
Mass of 2 moles of copper (i) oxide = 2 × 144 g = 288 g
Mass of Copper(i) oxide produced by 40 g of CuO will be: 40 × 288/160 = 72 g
Therefore, 72 g of Copper(i) oxide will be produced by 40 g of CuO.
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Why do hospitals use saline instead of distilled water?.
Explanation:
Normal saline contains Na+ and Cl-. Extracellularly,there is more Na+ and Cl- than intracellularly and most often during loss of bodily fluid,it is extracellular fluid that is lost and so the Na+ and Cl- ions in saline replenish these. Even if the loss of fluid is intracellular,it can still be replenished (passively )from the extracellular fluid into the intracellular fluid. Conversely, distilled water is just water which lacks any special electrolytes to carry out these functions as the normal saline
If 26.5 L of nitrogen at 748 mm Hg are compressed to 765 mm Hg at constant temperature. What is the new volume?
Answer:
25.91 L
Explanation:
P1V1= P2V2
748 (26.5) = 765 ( V2) V2 = 25.91 LITERS
When coal burns, the reaction
A. releases heat and is endothermic.
B. releases heat and is exothermic.
C. absorbs heat and is endothermic.
D. absorbs heat and is exothermic
why is the speed of these particles deffirent in each state
Answer:
due to difference ic kinetic energy
Explanation:
An air sample in an elastic bag has a volume of 3. 8 L when the temperature is 10 C. What will be the volume in liters when it is heated to 150 C?
At 10°C :
Volume = 3.8 LTemperature (in Kelvin) :
[tex]\qquad \tt \dashrightarrow \: 10 + 273[/tex]
[tex]\qquad \tt \dashrightarrow \: 283 \: k[/tex]
Now,
Temperature in Kelvin (at 150° C)
[tex]\qquad \tt \dashrightarrow \:150 + 173[/tex]
[tex]\qquad \tt \dashrightarrow \:323 \: k[/tex]
Now, let's find the volume (x) [ assume pressure to be constant ]
[tex]\qquad \tt \dashrightarrow \: \dfrac{V_1}{T_1} = \dfrac{V_2}{T_2}[/tex]
[tex]\qquad \tt \dashrightarrow \: \dfrac{3.8}{283} = \dfrac{x}{323}[/tex]
[tex]\qquad \tt \dashrightarrow \: \dfrac{3.8}{283} \times 323 = {x}[/tex]
[tex]\qquad \tt \dashrightarrow \: {x} \approx4.34 \: \: litres[/tex]
Types of isomers possible for ch3 ch2 ch2 ch3
Answer:
It has two isomers; n-butane and isobutane. Here n-butane is a straight-chain compound with four carbon atoms bonded with single covalent bonds. Explanation: Butane is an alkane with four carbon atoms so molecular formula is C4H10.
Explanation:
A conclusion drawn through reasoning is called an
evaluation
inference
oversight
understanding
how many moles of water are needed to react with 2.3 grams of sodium
Answer:
Brainliest pls
Explanation:
Theoretical yield = 0.1 g
Percent yield = 80%
Which indicator displays orange in acidic solutions?
Universal indicator
Methyl orange indicator
Thymol blue indicator
Phenol red indicator
Answer:
Explanation:
Universal indicator. The universal indicator turns orange in acidic solutions with a pH of
A student places a starch and water solution into a bag of dialysis tubing and then ties off the ends. Next, he places the filled bag into a beaker of distilled water. Water will now ________ the bag by the process of ________.
Answer:
After 30 minutes have passed, the solution inside the dialysis tubing and the solution in the beaker will be tested for glucose and starch
-The presence of glucose will be tested with Benedict's solution, Testape®, or Clinistix
In many titrations, you need to add an indicator that changes color when the titration is complete. The titration of sodium oxalate with potassium permanganate does not use an indicator. However, a pink color does appear to signal the end of the titration. What causes the color change signaling the completed titration of sodium oxalate with potassium permanganate?.
In the titration of sodium oxalate with potassium permanganate the pink color change is due to shift in equilibrium position of the reaction
What is chemical equilibrium?Chemical equilibrium is the equilibrium that exists between chemical species in which the rate of forward reaction is equal to the rate of backward reaction.
The pink color change in the that occurs in the titration of sodium oxalate with potassium permanganate is due to shift in equilibrium position of the reaction.
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Determine the mass of an object that has a volume of 88.6 mL and a density of 7.77 g/mL. 0.0877 g 80.8 g 96.37 g 688 g 11.4 g 10 points
Answer:
688g
Explanation:
This is the correct awnser
Give the full electron configuration for nitrogen.
Answer:
1s2 2s2 2p3
Explanation:
How are transform boundaries different from
convergent and divergent boundaries?
Answer:
As the plates travel horizontally past one other, no crust is formed nor destroyed.
Explanation: tectonic plates
Hazardous materials are grouped into classes identifying their.
Hazardous materials are grouped into classes identifying their similarities in composition and structure.
Why hazardous materials are grouped into classes?The hazardous materials are grouped into classes in order to tell us about the severity of hazard and it is done on the basis of similarity in composition.
So we can conclude that hazardous materials are grouped into classes identifying their similarities in composition and structure.
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What is the best method for monitoring the progress of reaction during the oxidation reaction of borneol to camphor
Answer:This reaction will be followed by TLC to monitor the progress of the oxidation. The camphor is then reduced by sodium borohydride to give the isomeric alcohol,
Explanation:
hopes this helps<33
File attached, i need an explanation too
33. Stan and Kenya are investigating the properties of gases in the lab. Stan has a balloon filled with helium, and Kenya has a balloon filled with hydrogen. Under which condition do the gases in the two balloons have the same kinetic energy?
same volume
same pressure
same temperature
same concentration
will give brainliest
If the sample of helium and nitrogen gas has the same kinetic energy, then it follows that hey have the same temperature.
Kinetic energy of gasesWe know that gas molecuules are in constant random motion hence they collide with each other as well as with the walls of the container. The temeprature of the gas determines the kinetic energy of the gas.
Hence if the sample of helium and nitrogen gas has the same kinetic energy, then it follows that hey have the same temperature.
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