5. Given the following data: + %O2(g) B2H6(g) + 302(g) + ½O2(g) H2O(1) 2B(s) B2O3(s) AH = -1273 kJ/mole B2O3(s) + 3H20(g) H2O(1) H2O(g) AH = -2035 kJ/mole H2(g) AH = -286 kJ/mole %3D AH = 44 kJ/mole Calculate AHrxn for the following reaction: 2B(s) + 3H2(g) B2H6(g) -> + 3/202(g) Reverse (b) B2O3(s) + 3H2O(g) 3x (c) 3H2(g) + 3/202(g) 3H20(1) (a) 2B(s) B2O3(s) B2H6(g) + 302(g) 3H2O(1) 3H20(g) AH = -1273 kJ/mole AH = +2035 kJ/mole %3D AH = -858 kJ/mole %3D Зx (d) AH = 132 kJ/mole 2B(s) + 3H2(g) - B2H6(g) AH = +36 kJ/mole %3D The reaction is ENDOTHERMIC because AH is positive

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.

When one mole of ethylene gas, C2H4, reacts with fluorine gas, hydrogen fluoride and carbon tetrafluoride gases are formed and 2496.7 kJ of heat are given off. What is Hf for CF4(g)?

A rebreathing gas mask contains potassium superoxide, KO2, which reacts with moisture in the breath to give oxygen. 4KO2(s)+2H2O(l)4KOH(s)+3O2(g) Estimate the grams of potassium superoxide required to supply a persons oxygen needs for one hour. Assume a person requires 1.00 102 kcal of energy for this time period. Further assume that this energy can be equated to the heat of combustion of a quantity of glucose, C6H12O6, to CO2(g) and H2O(l). From the amount of glucose required to give 1.00 102 kcal of heat, calculate the amount of oxygen consumed and hence the amount of KO2 required. The ff0 for glucose(s) is 1273 kJ/mol.

How much heat, in joules and in calories, must be added to a 75.0g iron block with a specific heat of 0.449 Jig C to increase its temperature from 25 C to its melting temperature of 1535 C?

In a calorimetric experiment, 6.48 g of lithium hydroxide, LiOH, was dissolved in water. The temperature of the calorimeter rose from 25.00C to 36.66C. What is H for the solution process? LiOH(s)Li(aq)+OH(aq) The heat capacity of the calorimeter and its contents is 547 J/C.

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.)

Graphite is burned in oxygen to give carbon monoxide and carbon dioxide. If the product mixture is 33% CO and 67% CO2 by mass, what is the heat from the combustion of 1.00 g of graphite?

When lightning strikes, the energy can force atmospheric nitrogen and oxygen to react to make NO: N2(g)+O2(g)2NO(g)H=+181.8kJ (a) Is this reaction endothermic or exothermic? (b) What quantities of reactants and products are assumed if H = +181.8 kJ? (c) What is the enthalpy change when 3.50 g nitrogen is reacted with excess O2(g)?

Consider the following reaction in a vessel with a movable piston. R(g)+T(g)X(g)As the reaction takes place, the piston loses 1072 J of heat. The piston moves down and the surroundings do 549 J of work on the system. What is E?