1. A student determines the molar mass of acetone, CH3COH3, by the method used in this experiment. She found that the equilibrium temperature of a mixture of ice and water was 0.5°C on her thermometer. When she added 10.5 g if her sample to the mixture, the temperature, fell to -2.6°C. She then poured off the solution through a screen into a beaker. The mass of the solution was 86.4g. a. What was the freezing point depression? °C b. What was the molality of the acetone? m c. How much acetone was in the decanted solution? d. How much water was in the decanted solution? e. How much acetone would there be in a solution containing 1 kg of water and acetone at the same concentration as she had in her experiment? g acetone f. What did she find to be the molar mass of acetone, assuming she made the calculation properly?

1. A student determines the molar mass of acetone, CH3COH3, by the method used in this experiment. She found that the equilibrium temperature of a mixture of ice and water was 0.5°C on her thermometer. When she added 10.5 g if her sample to the mixture, the temperature, fell to -2.6°C. She then poured off the solution through a screen into a beaker. The mass of the solution was 86.4g. a. What was the freezing point depression? °C b. What was the molality of the acetone? m c. How much acetone was in the decanted solution? d. How much water was in the decanted solution? e. How much acetone would there be in a solution containing 1 kg of water and acetone at the same concentration as she had in her experiment? g acetone f. What did she find to be the molar mass of acetone, assuming she made the calculation properly?

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

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1. A student determines the molar mass of acetone, CH,COH., by the method used in this experiment. She found that the equilibrium temperature of a mixture of ice and water was 0.5°C on her thermometer. When she added 10.5 g if her sample to the mixture, the temperature, fell to -2.6°C. She then poured off the solution through a screen into a beaker. The mass of the solution was 86.4g. d. How much water was in the decanted solution?
You have 0.500-L of a 0.275-M solution of acetone (C3H6O), initially at 37.0°C. You place a copper brick, initially at a temperature of 150.0°C, into the solution of acetone. The temperature of the acetone and copper brick at thermal equilibrium is 58.0°C. What was the mass of the copper brick? Assume the copper brick does not undergo a phase change over the course of the temperature change. Report your answer in units of g and to 3 significant figures. Hfus = 5.7 kJ/mol Hvap = 31.3 kJ/mol Cgas = 75.5 J/mol K Cliq = 125.5 J/mol K Csolid = 96 J/mol K Boiling Point of Acetone = 329 K Freezing Point of Acetone = 179 K
200.0 mL of 0.200 M HNO3 is added to 200.0 mL of 0.200 M KOH in a coffee cup calorimeter. The neutralization reaction that occurs can be described by the chemical equation- HNO3(aq) + KOH(aq) → KNO3(aq) + H₂O(l) Before the solutions are mixed they are both at 23.00 °C. After the mixing of the solutions the temperature increases until it remains constant at 24.39 °C. Assuming no heat lost to the surroundings, how much heat was lost in this reaction? (Assume the specific heats and densities of the solutions is the same as water.)
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A coffee-cup (constant pressure) calorimeter is used to carry out the following reaction in 68.5 mL water (where X is a hypothetical metal): X + 2 HCI ---> XCI2 + H2 In this process, the water temperature rose from 25.0 °C to 33.3 °C. If 0.00629 mol of "X" was consumed during the reaction, what is ?rH of this reaction in kJ mol^-1with respect to "X"? The specific heat of water is 4.184 J g-¹ °C-¹
Potassium nitrate, KNO3KNO3, has a molar mass of 101.1101.1 g/mol. In a constant-pressure calorimeter, 23.223.2 g of KNO3KNO3 is dissolved in 341341 g of water at 23.00 °C23.00 °C. KNO3(s)−→−−H2OK+(aq)+NO−3(aq)KNO3(s)→H2OK+(aq)+NO3−(aq) The temperature of the resulting solution decreases to 17.50 °C17.50 °C. Assume that the resulting solution has the same specific heat as water, 4.184 J/(g·°C)4.184 J/(g·°C), and that there is negligible heat loss to the surroundings. How much heat was released by the solution? ?soln=qsoln= kJkJ What is the enthalpy of the reaction? Δ?rxn=ΔHrxn= kJ/mol
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What is the change in enthalpy in joules when 5.44x10-4 mol of AgCl dissolves in water according to the following chemical equation: AgCl(s) → Ag⁺(aq) + Cl⁻(aq) ∆H =65.5 KJ I need the step-by-step process please & thank you!
Zinc metal reacts with hydrochloric acid according to the following balanced equation: Zn(s)+2HCl(aq)→ZnCl2(aq)+H2(g) When 0.128 gg of Zn(s) is combined with enough HCl to make 54.4mL of solution in a coffee-cup calorimeter, all of the zinc reacts, raising the temperature of the solution from 22.3 ∘C to 23.7 ∘C. Find ΔHrxn for this reaction as written. (Use 1.00 g/mL for the density of the solution and 4.18 J/(g⋅∘C) as the specific heat capacity.) Express your answer in kilojoules per mole to two significant figures.
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Consider a mixture of hexane and heptane as an ideal solution. In what proportion by mass should they be mixed to achieve the greatest ΔmixS?