2. When 4.21 grams of potassium hydroxide are added to 250. mL of water in a coffee cup calorimeter, the temperature rises by 4.14 °C. Assume that the density and specific heat of the dilute aqueous solution are the same as those of H2O and calculate the molar heat of solution of potassium hydroxide in kJ/mol. C = 4.184 J/g K

When 7.11 g NH4NO3 is added to 100 mL water, the temperature of the calorimeter contents decreases from 22.1 C to 17.1 C. Assuming that the mixture has the same specific heat as water and a mass of 107 g, calculate the heat q. Is the dissolution of ammonium nitrate exothermic or endothermic?

How much heat is produced when loo mL of 0.250 M HCl (density, 1.00 g/mL) and 200 mL of 0.150 M NaOH (density, 1.00 g/mL) are mixed? HCl(aq)+NaO(aq)NaCl(aq)+H2O(l)H298=58kJ If both solutions are at the same temperature and the heat capacity of the products is 4.19 J/g C, how much will the temperature increase? What assumption did you make in your calculation?

A 21.3-mL sample of 0.977 M NaOH is mixed with 29.5 mL of 0.918 M HCl in a coffee-cup calorimeter (see Section 6.6 of your text for a description of a coffee-cup calorimeter). The enthalpy of the reaction, written with the lowest whole-number coefficients, is 55.8 kJ. Both solutions are at 19.6C prior to mixing and reacting. What is the final temperature of the reaction mixture? When solving this problem, assume that no heat is lost from the calorimeter to the surroundings, the density of all solutions is 1.00 g/mL, the specific heat of all solutions is the same as that of water, and volumes are additive.

The heat of neutralization, Hneut, can be defined as the amount of heat released (or absorbed), q, per mole of acid (or base) neutralized. Hneut for nitric acid is -52 kJ/mol HNO3. At 27.3C, 50.00 mL of 0.743M HNO3 is neutralized by 1.00 M Sr(OH)2 in a coffee-cup calorimeter. (a) How many mL of Sr(OH)2 were used in the neutralization? (b) What is the final temperature of the resulting solution? (Use the assumptions in Question 11.)

Dissolving 6.00 g CaCl2 in 300 mL of water causes the temperature of the solution to increase by 3.43 C. Assume that the specific heat of the solution is 4.18 J/g K and its mass is 306 g. (a) Calculate the enthalpy change when the CaCl2 dissolves. Is the process exothermic or endothermic? (b) Determine H on a molar basis for CaCl2(s)H2OCa2+(aq)+2Cl(aq)

How much will the temperature of a cup (180 g) of coffee at 95 C be reduced when a 45 g silver spoon (specific heat 0.24 J/g C) at 25 C is placed in the coffee and the two are allowed to reach the same temperature? Assume that the coffee has the same density and specific heat as water.

A 29.1-mL sample of 1.05 M KOH is mixed with 20.9 mL of 1.07 M HBr in a coffee-cup calorimeter (see Section 6.6 of your text for a description of a coffee-cup calorimeter). The enthalpy of the reaction, written with the lowest whole-number coefficients, is 55.8 kJ. Both solutions are at 21.8C prior to mixing and reacting. What is the final temperature of the reaction mixture? When solving this problem, assume that no heat is lost from the calorimeter to the surroundings, the density of all solutions is 1.00 g/mL, and volumes are additive.

The addition of 3.15 g of Ba(OH)28H2O to a solution of 1.52 g of NH4SCN in loo g of water in a calorimeter caused the temperature to fall by 3.1 C. Assuming the specific heat of the solution and products is 4.20 J/g C, calculate the approximate amount of heat absorbed by the reaction, which can be represented by the following equation: Ba(OH)28H2O(s)+2NH4SCN(aq)Ba(SCN)2(aq)+2NH3(aq)+10H2O(l)

The thermochemical equation for the burning of methane, the main component of natural gas, is CH4(g)+2O2(g)CO2(g)+2H2O(l)H=890kJ (a) Is this reaction endothermic or exothermic? (b) What quantities of reactants and products are assumed if H = 890 kJ? (c) What is the enthalpy change when 1.00 g methane burns in an excess of oxygen?