8. Thermochemistry

Given the thermochemical equation CH4(g) + 2O2(g) → CO2(g) + 2H2O(g) with ΔH°rxn = -802.3 kJ, what minimum mass of CH4 is required to heat 85.0 g of water by 30.0 °C, assuming 100% heating efficiency? (For water, Cs = 4.18 J/g°C).

How much heat is absorbed when 30.00 g of C(s) reacts in the presence of excess SO2(g) to produce CS2(l) and CO(g) according to the following chemical equation? 5 C(s) + 2 SO2(g) → CS2(l) + 4 CO(g), ΔH = 239.9 kJ

Mothballs are composed primarily of the hydrocarbon naphthalene (C10H8). When 0.820 g of naphthalene burns in a bomb calorimeter, the temperature rises from 25.10 °C to 31.56 °C. Find ΔErxn for the combustion of naphthalene given that the heat capacity of the calorimeter is 5.50 kJ/°C.

Mothballs are composed primarily of the hydrocarbon naphthalene (C10H8). When 0.820 g of naphthalene burns in a bomb calorimeter, the temperature rises from 25.10 °C to 31.56 °C. Find ΔErxn for the combustion of naphthalene given that the heat capacity of the calorimeter is 5.90 kJ/°C.

Mothballs are composed primarily of the hydrocarbon naphthalene (C10H8). When 0.820 g of naphthalene burns in a bomb calorimeter, the temperature rises from 25.10 °C to 31.56 °C. If the heat capacity of the calorimeter is 5.11 kJ/°C, what is the ΔErxn for the combustion of naphthalene?

Sodium metal reacts with water to produce hydrogen gas and sodium hydroxide according to the chemical equation shown below. When 0.025 mol of Na is added to 100.00 g of water, the temperature of the resulting solution rises from 25.00°C to 35.75°C. If the specific heat capacity of water is 4.18 J/g°C, what is the enthalpy change (ΔH) for the reaction per mole of Na?

What is the approximate enthalpy change for the combustion of ethane in the reaction: 2 CH3-CH3(g) + 7 O2(g) → 4 CO2(g) + 6 H2O(g)?

The combustion of ethanol is shown below. C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(g) ΔH = –1367 kJ mol–1. The enthalpy change for the combustion of 12.5 g of ethanol is:

Which of the following reactions correctly represents the heat of hydration for the dissolution of gaseous sodium ions (Na+) in water?

In a coffee-cup calorimeter, 49.85g of 0.2 M HCl solution is mixed with 49.85g of 0.2 M NaOH solution, both initially at the same temperature. If the final temperature of the mixture is measured to be higher, what is the primary reason for this temperature change?

The ΔH for the solution process when solid sodium hydroxide dissolves in water is -44.4 kJ/mol. When a 12.89-g sample of NaOH (MM= 40.0 g/mol) dissolves in 250.00 g of water in a coffee-cup calorimeter, the temperature increases from 24°C to what final temperature?

Two solutions, initially at 24.69°C, are mixed in a coffee cup calorimeter. When a 200.0 mL volume of 0.100 M AgNO3 solution is mixed with a 100.0 mL sample of 0.100 M NaCl solution, the temperature in the calorimeter rises to 25.16°C. Determine the enthalpy change (ΔH) for the reaction, assuming the specific heat capacity of the solution is 4.18 J/g°C and the density is 1.00 g/mL.

Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction: 4 NO(g) + 2 O2(g) → 4 NO2(g). Given: N2(g) + O2(g) → 2 NO(g), ΔH°rxn = +183 kJ. What is the ΔH°rxn for the reaction 4 NO(g) + 2 O2(g) → 4 NO2(g)?

Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction: 4 S(s) + 6 O2(g) → 4 SO3(g). Given: SO2(g) → S(s) + O2(g) ΔH°rxn = +296.8 kJ, 2 SO2(g) + O2(g) → 2 SO3(g) ΔH°rxn = -198.2 kJ. What is the ΔH°rxn for the target reaction?

Given the following thermochemical equation and data, calculate the standard enthalpy of formation (ΔH⁰f) for IF(g): IF7(g) + I2(g) → IF5(g) + 2 IF(g) with ΔH⁰rxn = -89 kJ. The standard enthalpies of formation are: IF7(g) = -941 kJ/mol, IF5(g) = -840 kJ/mol, I2(g) = 62.42 kJ/mol.