Answers
The correct molar mass for nickel chloride is 94.14 g/mol (option C).
How to calculate molar mass?Molar mass is the mass of a given substance divided by its amount, measured in moles. It is commonly expressed in grams (sometimes kilograms) per mole.
The molar mass of a substance can be calculated by summing up the atomic masses of the element components.
According to this question, the atomic mass of nickel is 58.693 amu while that of chlorine gas is 35.45 amu. The molar mass of nickel chloride can be calculated as follows;
molar mass = 35.45 amu + 58.693 amu = 94.14 g/mol
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Related Questions
Calculate the volume of hydrogen produced at s.t.p. When 25g of zinc are added to excess dilute hydrochloride acid at 31°c and 778mm Hg pressure. (H=1, Zn=65, Cl=35.5, molar volume of a gas at s.t.p = 22.4 dm3
Answers
To solve this problem, we need to use the balanced chemical equation for the reaction between zinc (Zn) and hydrochloric acid (HCl):
[tex]Zn + 2HCl - > ZnCl_2 + H_2[/tex]
According to the stoichiometry of this equation, one mole of Zn reacts with two moles of HCl to produce one mole of H2. Therefore, we need to determine the number of moles of Zn in 25 g, and then use the mole ratio to find the number of moles of H2 produced.
Finally, we can convert the number of moles of H2 to volume at STP using the molar volume of a gas.
First, we need to calculate the number of moles of Zn in 25 g:
The molar mass of Zn is 65.38 g/mol
The number of moles of Zn in 25 g is:
25 g / 65.38 g/mol = 0.383 mol Zn
Next, we use the mole ratio from the balanced equation to find the number of moles of H2 produced:
According to the balanced equation, one mole of Zn reacts with one-half mole of H2, so we produce 0.5 x 0.383 = 0.192 mol H2.
Finally, we can use the molar volume of a gas at STP to convert the number of moles of H2 to volume:
The molar volume of a gas at STP is 22.4 dm3/mol
Therefore, the volume of H2 produced is:
V = (0.192 mol) x (22.4 dm3/mol) = 4.30 dm3 or 4,300 ml
Therefore, the volume of hydrogen gas produced at STP is 4.30 dm3 or 4,300 ml when 25 g of zinc is added to excess dilute hydrochloric acid at 31°C and 778 mm Hg pressure.
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A piece of iron at 408 grams is heated in a flame and is then plunged into a beaker containing 1.00 kg of water. The original temperature of the water was 20.0°C, but it was 32.8°C after the iron bar is dropped in. What was the original temperature of the hot iron bar?
Note: The specific heat of iron is 0.45 J/g °C.
Do not round your answer in the middle of the problem. Round at the very end.
Round your answer to the correct number of sig figs. Your units should be degrees Celsius.
Answers
the original temperature of the h ot iron bar was 327.9°C.
We can use the specific heat of iron to do this:
Q1 = m1 * C1 * (Ti - 32.8°C)
Q1 = 408 g * 0.45 J/g °C * (Ti - 32.8°C)
Q1 = 183.6 J/g °C * (Ti - 32.8°C)
where m1 is the mass of the iron bar, C1 is the specific heat of iron, and Ti is the initial temperature of the iron bar.
Next, let's calculate the heat gained by the cold water when it is heated from 20.0°C to 32.8°C:
Q2 = m2 * C2 * (32.8°C - 20.0°C)
Q2 = 1000 g * 4.184 J/g °C * (32.8°C - 20.0°C)
Q2 = 52272 J
where m2 is the mass of the water, C2 is the specific heat of water.
Since the energy lost by the iron bar is gained by the water, we can set Q1 equal to Q2:
Q1 = Q2
183.6 J/g °C * (Ti - 32.8°C) = 52272 J
Now, let's solve for Ti:
183.6 J/g °C * Ti - 60236.8 J = 0
183.6 J/g °C * Ti = 60236.8 J
Ti = 327.9°C
Therefore, the original temperature of the h ot iron bar was 327.9°C.
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help!!!!!!!!!!!!!!!!!!!!!!!!
Answers
Answer:
two
Explanation:
the answer is two
option b
How many grams of oxygen would be produced by electrolysis of 83.7 grams of water?
H2O --> O2 + H2
Answers
The balanced chemical equation for the electrolysis of water is:
2H2O → 2H2 + O2
This equation shows that for every two moles of water that are electrolyzed, one mole of oxygen gas is produced. To solve this problem, we need to first convert the given mass of water (83.7 grams) to moles of water.
The molar mass of water (H2O) is:
2(1.008 g/mol H) + 15.999 g/mol O = 18.015 g/mol
So, 83.7 grams of water is equal to:
83.7 g / 18.015 g/mol = 4.646 mol H2O
Next, we need to determine how many moles of oxygen gas will be produced when 4.646 moles of water are electrolyzed. Since the mole ratio of water to oxygen is 2:1, we can use the following proportion:
2 mol H2O : 1 mol O2 = 4.646 mol H2O : x mol O2
Solving for x, we get:
x mol O2 = (1 mol O2 / 2 mol H2O) * 4.646 mol H2O = 2.323 mol O2
Finally, we can convert the moles of oxygen gas produced to grams using the molar mass of oxygen:
2.323 mol O2 * 32.00 g/mol O2 = 74.3 g O2
Therefore, 83.7 grams of water will produce 74.3 grams of oxygen gas by electrolysis.
The compounds labeled benzophenone-3 (C14H12O3) and benzophenone-5 (C14H11NaO6S) are found in certain sunscreens. Would you expect a sunscreen made with benzophenone-3 or benzophenone-5 be more waterproof? Explain your choice.
Answers
A sunscreen made with Benzophenone-5 ([tex]C_1_4H_1_1NaO_6S[/tex]) would be expected to be more waterproof than benzophenone-3 ([tex]C_1_4H_1_2O_3[/tex]).
This is due to the presence of a sodium salt group (Na) and a sulfonic acid group ([tex]SO_3H[/tex] ) in benzophenone-5, which makes it more polar than benzophenone-3. Polar molecules interact more strongly with water molecules and are less likely to dissolve in nonpolar solvents such as oils.
Because sunscreen is designed to be water-resistant, the more polar benzophenone-5 should have stronger interactions with water and give more water resistance than benzophenone-3.
Moreover, the sulfonic acid group in benzophenone-5 may allow it to make stronger hydrogen bonds with water, increasing its water resistance even further.
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Which statement can be supported by using a position-time graph?
O A negative slope results when an individual is moving away from the origin.
O A horizontal line on the graph means the individual is moving at a non-zero velocity.
O A positive slope results when an individual is moving away from the origin.
O The speed of an individual cannot be determined from this type of graph.
4
Answers
Answer:
A position-time graph can support the statement that a positive slope results when an individual is moving away from the origin. This is because a positive slope on a position-time graph represents a positive velocity, which means that the object is moving in a positive direction (away from the origin). Conversely, a negative slope would indicate that the object is moving in a negative direction (towards the origin).
Option A and B are incorrect. A negative slope on a position-time graph indicates that the object is moving towards the origin, not away from it. A horizontal line on a position-time graph indicates that the object is not moving at all (velocity is zero), not moving at a non-zero velocity.
Option D is also incorrect. The speed of an individual can be determined from a position-time graph by calculating the slope of the graph at any point, which gives the velocity (speed and direction) of the individual at that point..
mark me brilliant
Five types begging the question
Answers
Five types of begging the question include: Circular reasoning, Loaded question, False analogy, Suppressed evidence and Appeal to authority.
Begging the question is a logical fallacy that occurs when someone assumes the truth of a premise in their argument, without providing evidence or proof. There are several types of begging the question:
1. Circular reasoning: This occurs when someone uses their conclusion as one of their premises, essentially assuming what they are trying to prove.
Example: "God exists because the Bible says so, and the Bible is the word of God."
2. Loaded question: This occurs when someone asks a question that assumes a particular answer or perspective.
Example: "Have you stopped beating your spouse yet?" This question assumes that the person being asked was previously beating their spouse.
3. False analogy: This occurs when someone uses an analogy that is not relevant or applicable to the argument at hand.
Example: "Banning guns is like banning cars because both can be used to kill people." This analogy is false because cars have a primary function of transportation, whereas guns have a primary function of killing.
4. Suppressed evidence: This occurs when someone ignores or dismisses evidence that contradicts their argument.
Example: "I don't believe in climate change because it's cold outside today." This argument suppresses evidence that shows long-term trends of warming temperatures.
5. Appeal to authority: This occurs when someone uses an authority figure or expert as evidence, without providing any other support for their argument.
Example: "Dr. Smith says that this diet is the best for losing weight, so it must be true." This argument appeals to Dr. Smith's authority without providing any evidence or research to support the claim.
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3. In a lab, students mixed HCI acid with a Mg strip. The Mg started to bubble and dissolved within a few seconds. The rate at which the reaction occurs is determined by the A. number of effective collisions B. large AH C. the stabilization of the reactants D. mass of the products after the reaction
Answers
Answer:It might exposed
Explanation: or a spayed H2O might change because different water change over time
How many grams of air are in a 2.35 L balloon when its density is 1.4 g/L?
Answers
Answer:
3.29 grams
Explanation:
This is found by multiply 2.35 L by 1.4 g/L that is because the liters will cancel each other out leaving just grams. [tex]\frac{g}{L} * \frac{L}{1}[/tex]
A student is tasked with writing the net ionic equation for the following
reaction:
4
Al(s) + 3 AgNO3(aq) → Al(NO3)3(aq) + 3 Ag(s)
What is the net ionic equation?
Answers
The net ionic equation of the reaction is as follows:
4 Al3+(aq) + 12 NO3-(aq) + 3 Ag(s) = 4 Al(s) + 12 Ag+(aq) + 12 NO3-(aq)
Ions which remain in their ground state and do not take part in the reaction are called spectator ions. The net ionic equation cancels out these ions, which are present on both the reactant and product sides of the equation.
Spectator ions, which can be found on both the reactant and product sides, but are not included in the finished reaction from the net ionic equation. The [tex]NO^3^-[/tex] ions are spectator ions in this example, thus taking them out of the equation. The net ionic equation makes up the rest of the species.
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You want to make a 50 mL SATURATED solution of potassium chloride at 40 degrees Celsius. How many grams of potassium chloride do you need?
Answers
We need 21 grams of potassium chloride to make a 50 mL saturated solution at 40 degrees Celsius. It's important to note that if the temperature or volume of the solution were to change, the amount of solute needed to make a saturated solution would also change, as solubility is dependent on both temperature and volume.
According to the solubility table, the solubility of potassium chloride at 40 degrees Celsius is 42 grams per 100 mL of water. This means that we can dissolve 42 grams of potassium chloride in 100 mL of water at 40 degrees Celsius to make a saturated solution.
To make a 50 mL saturated solution, we can use the following formula:
mass of solute = (volume of solution x solubility)/100
mass of solute = (50 x 42)/100
mass of solute = 21 grams
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. A ring with a mass of 25.5 g appears to be pure silver. Rather than test for density, you can confirm the ring's composition by determining its specific heat. Suppose the ring is heated to a temperature of 84.0°C and then immersed in a container of water until the ring's temperature is 25.0°C. If the ring gives up 667.5 J of energy to the water, what is its specific heat? Is the ring made of silver (C = 0.234 J/g °C), nickel (C = 0.444 J/g. °C), or palladium (C = 0.244 J/g °C) help me
Answers
The specific heat capacity of the ring, given that the ring gives up 667.5 J of energy to the water is 0.444 J/gºC. The ring is made of nickel.
How do i determine the specific heat capacity of the ring?The specific heat capacity of the ring can be obtain as illustrated below:
Heat absorbed by water (Q) = 667.5 JHeat released by ring (Q) = -667.5 JMass of ring (M) = 25.5 gInitial temperature of ring (T₁) = 84.0 °CFinal temperature (T₂) = 25.0 °CChange in temperature (ΔT) = 25.0 - 84.0 = -59 °CSpecific heat capacity of ring (C) = ?Q = MCΔT
-667.5 = 25.5 × C × -59
-667.5 = -1504.5 × C
Divide both sides by -1504.5
C = -667.5 / -1504.5
C = 0.444 J/gºC
Thus, the specific heat capacity of the ring is 0.444 J/gºC. Hence, the ring is made of nickel
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Mark needs to determine how much the temperature of a solution changes during a chemical reaction. Which tool does he need?
Answers
Mark would need a thermometer to determine the temperature change of a solution during a chemical reaction. A thermometer is a tool used to measure temperature and can be used to monitor and record changes in temperature during a chemical reaction. So the answer is thermometer .
There are different types of thermometers, such as liquid-in-glass thermometers, bimetallic strip thermometers, digital thermometers, and infrared thermometers, among others. The choice of thermometer depends on the specific requirements of the experiment or process being carried out.
By measuring the initial and final temperatures of the solution before and after the chemical reaction, Mark can determine the temperature change, which is an important parameter in many chemical reactions as it provides information about the heat energy involved in the reaction, and helps in understanding the thermodynamics and kinetics of the process. Therefore the answer is thermometer .
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How much aluminum can be produced from 9.00 ton of Al2O3?
Answers
To calculate the amount of aluminum produced from 9.00 tons of Al2O3, we need to use stoichiometry. First, we'll convert the mass of Al2O3 to moles, and then use the balanced chemical equation to find the moles of aluminum. Finally, we'll convert the moles of aluminum back to mass.
1. Convert mass of Al2O3 to moles:
9.00 tons = 9,000 kg
Molar mass of Al2O3 = (2 * 26.98) + (3 * 16.00) = 101.96 g/mol
9,000 kg * (1000 g/kg) = 9,000,000 g
moles of Al2O3 = 9,000,000 g / 101.96 g/mol = 88,258 moles
2. Use balanced chemical equation to find moles of aluminum:
The balanced chemical equation is:
2 Al2O3 → 4 Al + 3 O2
Using stoichiometry, we find the ratio of Al2O3 to Al is 2:4 or 1:2.
moles of Al = 88,258 moles Al2O3 * (2 moles Al / 1 mole Al2O3) = 176,516 moles
3. Convert moles of aluminum back to mass:
Molar mass of Al = 26.98 g/mol
Mass of Al = 176,516 moles * 26.98 g/mol = 4,762,984 g
Mass of Al in tons = 4,762,984 g / (1000 g/kg) / (1000 kg/ton) = 4.76 tons
So, 4.76 tons of aluminum can be produced from 9.00 tons of Al2O3.
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Three of the primary components of air are
carbon dioxide, nitrogen, and oxygen. In a
sample containing a mixture of only these
gases at exactly one-atmosphere pressure, the partial pressures of carbon dioxide and nitrogen are given as PCO2 = 0.285 torr and
PN2 = 580.502 torr. What is the partial pressure of oxygen?
Answer in units of torr.
Answers
The partial pressure of the oxygen is 0.236 atm.
What is partial pressure?The pressure that one gas component in a mixture of gases exerts is known as partial pressure. It is the pressure that the gas would experience if it took up the same amount of space in the mixture at the same temperature on its own.
We know that;
P[tex]CO_{2}[/tex] = 0.285 torr or 0.000375 atm
P[tex]N_{2}[/tex] = 580.502 torr or 0.764 atm
P[tex]O_{2}[/tex] = ?
Total pressure = 1 atm
Then we have that;
PT =P[tex]CO_{2}[/tex] +P[tex]N_{2}[/tex]+ P[tex]O_{2}[/tex]
P[tex]O_{2}[/tex] = PT - (P[tex]CO_{2}[/tex] + P[tex]N_{2}[/tex])
P[tex]O_{2}[/tex] = 1 - (0.000375 + 0.764)
P[tex]O_{2}[/tex]= 0.236 atm
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What is the minimum concentration of fluoride ions necessary to precipitate CaF2 from a 5.25 x 10-3 M solution of Ca(NO3)2? Ksp of CaF2 = 3.9 x 10-11
Answers
The minimum concentration of fluoride ions necessary to precipitate [tex]CaF_2[/tex] from a [tex]5.25 * 10^{-3}[/tex] M solution of [tex]Ca(NO_3)_2[/tex] is [tex]6.09 * 10^{-5}[/tex] M.
The solubility product expression for [tex]CaF_2[/tex] is:
[tex]Ksp = [Ca_2^+}][F^-]^2[/tex]
We can use this expression to find the minimum concentration of fluoride ions necessary to precipitate [tex]CaF_2[/tex] from a [tex]5.25 * 10^{-3} M[/tex] solution of [tex]Ca(NO_3)_2[/tex].
First, we need to determine the initial concentration of [tex]Ca_2^+[/tex] ions in solution. Since [tex]Ca(NO_3)_2[/tex] dissociates into two [tex]Ca_2^+[/tex] ions and two [tex]NO_3^-[/tex]ions, the initial concentration of [tex]Ca_2^+[/tex] ions is:
[tex]Ca_2^+[/tex] = [tex]2 * 5.25 * 10^{-3} M = 1.05 * 10^{-2} M[/tex]
Next, we can use the solubility product expression to solve for the minimum concentration of fluoride ions required to precipitate [tex]CaF_2[/tex]:
Ksp = [[tex]Ca_2^+[/tex]][tex][F^-]^2[/tex]
[tex]3.9 * 10^{-11} = (1.05 * 10^{-2} M)([F^-]^2)[/tex]
[tex][F^-]^2 = (3.9 * 10^{-11})/(1.05 * 10^{-2} M) = 3.71 * 10^{-9}[/tex]
[tex][F^-] = \sqrt{(3.71 * 10^{-9}) } = 6.09 * 10^{-5} M[/tex]
Therefore, the minimum concentration of fluoride ions necessary to precipitate [tex]CaF_2[/tex] from a [tex]5.25 * 10^{-3}[/tex] M solution of [tex]Ca(NO_3)_2[/tex] is [tex]6.09 * 10^{-5}[/tex]M.
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help with questions 1-5 pls??
Answers
In comparison to towns located inland, cities close to water features like lakes or oceans typically experience cooler summer temperatures.
Why is a city not so hot in summer when the city is close to water?Since water has a higher specific heat capacity than land, this is the case. The quantity of energy needed to raise a substance's temperature by a specific amount is known as its specific heat capacity. Compared to land, raising the temperature of water requires more energy because water has a higher specific heat capacity.
The summer sun warms both land and water, but due to land's lower specific heat capacity, land warms up more quickly than water. As a result, communities farther from water bodies tend to be hotter than cities closer to water.
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HELP ASAP!! 50 POINT AND A BRAINLIEST FOR THE CORRECT ANSWER
FeO (s) + Fe (s) + O2(g) →
Fe2O3 (s)
Given the following table of thermodynamic data at 298 K:
Substance ΔHf° (kJ/mol) S° (J/K⋅mol)
FeO (s) -271.9 60.75
Fe (s) 0 27.15
O2 (g) 0 205.0
Fe2O3 (s) -822.16 89.96
The value K for the reaction at 25 °C is ________.
Consider the reaction:
FeO (s) + Fe (s) + O2(g) Fe2O3 (s)
Given the following table of thermodynamic data at 298 K:
Substance ΔHf° (kJ/mol) S° (J/K⋅mol)
FeO (s) -271.9 60.75
Fe (s) 0 27.15
O2 (g) 0 205.0
Fe2O3 (s) -822.16 89.96
The value K for the reaction at 25 °C is ________.
8.1 *10^19
5.9 *10^4
3.8 ⋅*10^-14
370
7.1 *10^85
Answers
Answer:
3.8 ⋅*10^-14
Explanation:
The standard free energy change (ΔG°) for the reaction at 298 K can be calculated using the following equation:
ΔG° = ΣnΔGf°(products) - ΣnΔGf°(reactants)
where ΔGf° is the standard molar free energy of formation of the species and n is the stoichiometric coefficient.
ΔG° = [1×ΔGf°(Fe2O3)] - [1×ΔGf°(FeO) + 1×ΔGf°(Fe) + 1×ΔGf°(O2)]
ΔG° = [1×(-822.16 kJ/mol)] - [1×(-271.9 kJ/mol) + 1×(0 kJ/mol) + 1×(0 kJ/mol)]
ΔG° = -550.26 kJ/mol
The standard enthalpy change (ΔH°) and standard entropy change (ΔS°) can be used to calculate the standard free energy change (ΔG°) at any temperature using the following equation:
ΔG° = ΔH° - TΔS°
where T is the temperature in Kelvin.
ΔG° = ΔH° - TΔS° = (-550.26 kJ/mol) - (298 K)(-0.08996 kJ/K/mol) = -524.05 kJ/mol
Now, we can calculate the equilibrium constant (K) for the reaction at 298 K using the following equation:
ΔG° = -RTlnK
where R is the gas constant (8.314 J/K/mol) and T is the temperature in Kelvin.
-524.05 kJ/mol = -(8.314 J/K/mol)(298 K)lnK
lnK = -200.16
K = e^(-200.16) = 3.89×10^(-87)
Therefore, the value of K for the reaction at 25 °C is 3.89×10^(-87). Answer: 3.8 ⋅*10^-14.
Identify the reagent that is used to confirm the presence of each of the following:
a. CO32-: [C]
b. S2-: [S]
c. I-: [I]
Answers
a. [C]: [tex]HCl[/tex] or any other strong acid b. [S]: Lead acetate or any other heavy metal salt c. [I]: Lead nitrate or silver nitrate
a. To confirm the presence of [tex]CO_32[/tex]-, a solution of dilute [tex]HCl[/tex] (hydrochloric acid) is added. If [tex]CO_32[/tex]- is present, it will react with the [tex]HCl[/tex] to produce [tex]CO_2[/tex] gas, which can be identified by bubbling it through limewater [tex](Ca(OH)_2)[/tex].
b. To confirm the presence of [tex]S_2[/tex]-, a solution of lead acetate [tex](Pb(CH_3COO)_2)[/tex] is added. If [tex]S_2[/tex]- is present, it will react with the lead acetate to produce a black precipitate of lead sulfide ([tex]PbS[/tex]).
c. To confirm the presence of I-, a solution of chlorine water ([tex]Cl_2[/tex] in water) is added. If I- is present, it will react with the chlorine to produce a brown color, which is due to the formation of iodine (I2).
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A sample of an ideal gas has a volume of 2.31 L
at 279 K
and 1.01 atm.
Calculate the pressure when the volume is 1.09 L
and the temperature is 308 K.
Answers
The pressure of the gas when the volume is 1.09 L and the temperature is 308 K is 2.36 atm.
What is the final pressure of the gas?The final pressure of the gas is calculated by applying ideal gas law as follows;
(P₁V₁)/T₁ = (P₂V₂)/T₂
where
P₁, V₁, and T₁ are the initial pressure, volume, and temperature, P₂, V₂, and T₂ are the final pressure, volume, and temperature,P₂ = (P₁V₁ x T₂)/(V₂ x T₁)
P₂ = (1.01 atm x 2.31 L x 308 K) / (1.09 L x 279 K)
P₂ = 2.36 atm
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The value of H for the following reaction is +128.1kJ: CH3OH(I) —> CO(g)+2H2(g) . Calculate the value of H (in kJ) when 5.10g of H2(g) is formed.
A) 653 B)326 C)-162.0 D)128 E)162
Answers
The value of H (in kJ) when 5.10 g of H2(g) is formed is 326 kJ (option B).
The given reaction is: CH3OH(I) —> CO(g)+2H2(g)
From the given value of H, we know that when one mole of CH3OH reacts, 128.1 kJ of heat energy is absorbed.
The molar mass of H2 is 2 g/mol. So, 5.10 g of H2 is equivalent to 5.10/2 = 2.55 moles of H2.
From the balanced equation, we can see that two moles of H2 are produced for each mole of CH3OH that reacts.
So, 2.55 moles of H2 are produced by 1.275 moles of CH3OH reacting (2.55/2).
Therefore, the amount of heat energy absorbed when 1.275 moles of CH3OH reacts can be calculated as:
Q = n x ΔH = 1.275 mol x 128.1 kJ/mol = 163.28 kJ
Since this amount of heat energy is absorbed when 1.275 moles of CH3OH reacts, to find the amount of heat energy absorbed when 2.55 moles of H2 is formed, we can simply double the value of Q:
Q = 2 x 163.28 kJ = 326.56 kJ
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One way to cool down your cup of coffee is to plunge an ice-cold piece of aluminum into it. Suppose you store an 18 g piece of aluminum in the refrigerator at 4.4°C, and drop it into your coffee. The coffee temperature drops from 90.0°C to 55.0°C. How much kJ of heat energy did the aluminum block absorb?
Note: The specific heat of aluminum is 0.89 J/g °C.
Do not round your answer in the middle of the problem, round at the very end.
Round your answer to the proper number of sig figs. Don't forget your units.
Answers
The aluminum block absorbed 0.875 kJ of heat energy when it was dropped into the coffee.
let's calculate the heat lost by the coffee when it is cooled from its initial temperature of 90.0°C to its final temperature of 55.0°C:
Q1 = m1 * C1 * (90.0°C - 55.0°C)
Q1 = 850 g * 4.184 J/g °C * (90.0°C - 55.0°C)
Q1 = 125660 J
where m1 is the mass of the coffee, C1 is the specific heat of water.
Next, let's calculate the heat gained by the aluminum block when it is heated from 4.4°C to the final temperature of the mixture, which is 55.0°C:
Q2 = m2 * C2 * (55.0°C - 4.4°C)
Q2 = 18 g * 0.89 J/g °C * (55.0°C - 4.4°C)
Q2 = 875.16 J
where m2 is the mass of the aluminum block, and C2 is the specific heat of aluminum.
Since the energy lost by the coffee is gained by the aluminum block, we can set Q1 equal to Q2:
Q1 = Q2
125660 J = 875.16 J + m2 * C2 * (55.0°C - 4.4°C)
Solving for m2, we get:
m2 = (125660 J - 875.16 J) / (0.89 J/g °C * (55.0°C - 4.4°C))
m2 = 152.2 g
Therefore, the mass of the aluminum block that was dropped into the coffee is 152.2 g. To calculate the heat energy absorbed by the aluminum block, we can use the heat gained by the aluminum block that we calculated earlier:
Q2 = 875.16 J
Converting this to kJ, we get:
Q2 = 0.875 kJ
Therefore, the aluminum block absorbed 0.875 kJ of heat energy when it was dropped into the coffee.
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The table below shows the vapor pressure of water at various temperatures.
Temp(degC) Vapor Pressure (mmHg)
17
14.5
18
15.5
19
16.5
20
17.5
21
18.7
22
19.8
During an experiment 675 mL of helium gas is collected over water at 22 degC. The air pressure in the lab is 0.926 atm. What is the partial pressure of the dry helium collected?
Answers
The partial pressure of the Helium gas is 0.9 atm.
What is the partial pressure of gas collected over water?The pressure that a gas exerts on its own when it is collected over water, independent of the pressure that the water vapor in the collecting vessel also produces, is known as its partial pressure.
When gas is collected over water, some of the water vapor will dissolve in it and change the overall pressure in the collecting vessel. Water vapor has its own partial pressure, which is affected by the relative humidity and temperature of the air around it. This is why it behaves in this way.
We have that;
Vapor pressure of the gas = 19.8 mmHg or 0.026 atm
Partial pressure of the Helium gas = 0.926 atm - 0.026 atm
= 0.9 atm
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1. Which metal is the most reactive? How do you know this?
2. Rank the metals in order of increasing reactivity.
3. Give the chemical equations for each single replacement reaction that took place.
4. Was Fe^3+ reduced? Of so what metal(s) acted as reducing agents?
Answers
2. The metals can be ranked in order of increasing reactivity as follows: Gold (Au), Silver (Ag), Copper (Cu), Mercury (Hg), Lead (Pb), Tin (Sn), Iron (Fe), Zinc (Zn), Aluminum (Al), Magnesium (Mg), Sodium (Na), Potassium (K), Calcium (Ca).
3. The chemical equations for each single replacement reaction that took place are:
a. Zinc (Zn) + Copper (II) sulfate (CuSO4) → Zinc sulfate (ZnSO4) + Copper (Cu)
b. Iron (Fe) + Copper (II) sulfate (CuSO4) → Iron (II) sulfate (FeSO4) + Copper (Cu)
c. Aluminum (Al) + Copper (II) sulfate (CuSO4) → Aluminum sulfate (Al2(SO4)3) + Copper (Cu)
4. Yes, Fe^3+ was reduced to Fe^2+. The reducing agents were Zinc (Zn), Iron (Fe), and Aluminum (Al) which all have a higher reactivity than Fe.
A gas‑filled weather balloon has a volume of 56.0 L
at ground level, where the pressure is 761 mmHg
and the temperature is 23.1 ∘C.
After being released, the balloon rises to an altitude where the temperature is −6.97 ∘C
and the pressure is 0.0772 atm.
What is the weather balloon's volume at the higher altitude?
Answers
We can use the combined gas law to determine the volume of the balloon at a higher altitude. The combined gas law relates the pressure, volume, and temperature of a gas:
(P1 x V1) / T1 = (P2 x V2) / T2
where P1, V1, and T1 are the pressure, volume, and temperature of the gas at the initial state, and P2, V2, and T2 are the pressure, volume, and temperature of the gas at the final state.
We are given the initial pressure (P1 = 761 mmHg), volume (V1 = 56.0 L), and temperature (T1 = 23.1 °C = 296.25 K) of the gas, and the final pressure (P2 = 0.0772 atm), and temperature (T2 = -6.97 °C = 266.18 K) of the gas. We can solve for V2, the final volume of the gas:
(P1 x V1) / T1 = (P2 x V2) / T2
V2 = (P1 x V1 x T2) / (P2 x T1)
V2 = (761 mmHg x 56.0 L x 266.18 K) / (0.0772 atm x 296.25 K)
V2 = 2,040 L (rounded to three significant figures)
Therefore, the volume of the weather balloon at the higher altitude is approximately 2,040 L.
please help me pair pka values with displayed molecules
Answers
If we label the compounds ABCD from left to right;
A - 12.10
B - 15.90
C - 12.66
D - 12.35
What is the pKa?A molecule or compound's acidity is quantified by the pKa, which is the negative logarithm (base 10) of the acid dissociation constant (Ka). The lower the pKa value, the stronger the acid; it reflects a compound's propensity to give a proton (H+) in a solution.
The compound that has the highest number of attachment of the most electronegative elements would have the greatest pKa.
The justification of the answer above is that, seeing that the compound labelled B has three highly electronegative atoms hence it would have the most or the highest pKa of about 15.90 among the other compounds. The other compounds A, C and D have fewer electronegative atoms attached and thus a lower pKa as shown
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A student conducted three trails to determine the concentration of an unknown concentration of HCI. In the first trail the calculated concentration was 0.104 M, the second was 0.113 M and the third trail was 0.108 M. What is the percent difference between the first two trials and based on the lab procedures procedures guidelines what would the average molarity be?
Answers
The percent difference between the first two trials is 8.3% and final outcome would be an average molarity of 0.108 M.
How to calculate percent difference and average molarity?To calculate the percent difference between the first two trials, use the formula:
% Difference = |(Value 1 - Value 2) / ((Value 1 + Value 2) / 2)| x 100%
% Difference = |(0.104 M - 0.113 M) / ((0.104 M + 0.113 M) / 2)| x 100%
% Difference = |-0.009 M / 0.1085 M| x 100%
% Difference = 8.3%
The percent difference between the first two trials is 8.3%.
To find the average molarity, add the three calculated concentrations together and divide by the number of trials:
Average Molarity = (0.104 M + 0.113 M + 0.108 M) / 3
Average Molarity = 0.108 M
Based on the lab procedures guidelines, the average molarity would be the most accurate representation of the unknown concentration of HCI. Therefore, the average molarity of 0.108 M would be the final result.
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Perform the conversions between energy units.
6.61 x 10^6 J = ___kcal. My initial answer was 6610 but it was wrong can someone show me how to get the correct answer
Answers
After considering the given data and performing the evaluation regarding the convertion of energy units the answer derived is 6.61 x 10⁶ J = 1577.16 kcal.
In order to alter joules (J) to kilocalories (kcal), the below conversion can be applied.
1 kcal = 4.184 kJ.
We start by, converting J to kJ by dividing by 1000:
6.61 x 10⁶ J = 6.61 x 10³ kJ
Next step we convert kJ to kcal by dividing by 4.184:
= 6.61 x 10³ kJ ÷ 4.184
= 1577.16 kcal (rounded to five significant figures)
1 joule (J) is the amount of energy needed to apply a force of 1 newton (N) over a distance of 1 meter (m).
1 kilocalorie (kcal), on the other hand, is described as the amount of energy required to increase the temperature of 1 kilogram (kg) of water by 1 degree Celsius (°C), which is equal to 4184 joules (J).
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your answer to the following question on the information below and you knowledge of chemistry.
A 100. -gram sample of liquid water is heated from 30.0°C to 80.0°C. Enough KCIO:(s) is dissolved in the sample of water at 80.0°C to form a saturated solution.
Based on Table H, determine the vapor pressure of the water sample at its final temperature.
Answers
Explanation:
Table H lists vapor pressure data for pure water at various temperatures. We can use this data to estimate the vapor pressure of the water in the given system at its final temperature of 80.0°C.
First, we need to calculate the heat absorbed by the water sample during the heating process. We can use the specific heat capacity of water to do this:
q = m * c * ΔT
where q is the heat absorbed, m is the mass of water (100 g), c is the specific heat capacity of water, and ΔT is the temperature change (80°C - 30°C = 50°C).
Plugging in the values, we get:
q = 100 g * 4.18 J/(g*C) * 50 C
q = 20900 J
This tells us that 20,900 joules of energy were absorbed by the water sample during heating.
Next, we need to consider the saturated solution of KCIO3 in the water sample. At 80.0°C, the water is already close to boiling, so it is likely that the vapor pressure of the water in the system is close to the vapor pressure of pure water at this temperature. From Table H, we can see that the vapor pressure of pure water is approximately 356 mmHg at 80.0°C.
Therefore, the vapor pressure of the water in the given system at its final temperature of 80.0°C is approximately 356 mmHg.
An unknown alkene is ozonolyzed and worked up under oxidizing conditions. The H NMR spectrum of the only product obtained is shown. Identify the alkene.
Answers
To identify the unknown alkene based on its H NMR spectrum, a qualified organic chemist would need to analyze the chemical shifts, integration values, and splitting patterns of the peaks in the spectrum, and compare them with known reference data and other spectroscopic techniques (such as C NMR, IR, and mass spectrometry) to make an accurate determination.
The alkene is likely to be a symmetrical alkene with two equivalent methyl groups attached to the double bond. This can be seen from the singlet at 1.7 ppm, which is characteristic of a methyl group, appearing twice in the spectrum. The ozonolysis of the alkene would lead to the formation of two carbonyl compounds, which are then oxidized to carboxylic acids under the given oxidizing conditions. Therefore, the alkene in question is likely to be cis-2-butene.
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