When 0.418 g of pentene, C5H12, is burned in a bomb calorimeter, the temperature rises by 4.21 °C. The heat capacity of the calorimeter is 2.46 kJ/°C. Calculate the combustion energy (ΔE) for pentene, C5H12, in kJ/g.

The heat of vaporization of water at 100°C is 40.66 kJ/mol. Calculate the quantity of heat that is absorbed or released when 20.00 g of steam condenses to liquid water at 100°C.

The reaction NO2(g) + CO(g) → NO(g) + CO2(g) occurs in one step with an activation energy of 132 kJ/mol and a ΔE of -226 kJ/mol. Is this reaction endothermic or exothermic?

The temperature rises from 25.00°C to 29.00°C when 3.50 g of sucrose (C12H22O11, molar mass 342.3 g/mol) undergoes combustion in a bomb calorimeter. Calculate ΔE for the combustion of sucrose in kJ/mol sucrose, given that the heat capacity of the calorimeter is 4.50 kJ/°C.

Two solutions, initially at 24.60°C, are mixed in a coffee cup calorimeter. When a 100.0 mL volume of 0.100 M AgNO3 solution is mixed with a 100.0 mL sample of 0.200 M NaCl solution, the temperature in the calorimeter rises to 25.30°C. Determine the type of reaction that occurred.

When 1.045 g of Na2O is added to 50.0 mL of water at 25.0 °C in a calorimeter, the temperature of the water increases to 54.4 °C. Assuming that the specific heat of the solution is 4.18 J/(g·°C) and that the calorimeter itself absorbs a negligible amount of heat, calculate the heat absorbed by the solution.

When 12.2 g of an ionic compound (molar mass = 86.49 g/mol) is dissolved in 133 g of water in a coffee-cup calorimeter, the temperature changes from 21.24 °C to 16.34 °C. Calculate ΔHsolution for this ionic compound in kJ/mol. Use c = 4.18 J/(g°C) for water.

When 4.00 g of Ba(s) is added to 50.00 g of water in a container open to the atmosphere, the reaction shown below occurs, and the temperature of the resulting solution rises from 22.00°C to 77.62°C. If the specific heat of the solution is 4.18 J/(g°C), what is the nature of the reaction?

When 5.03 g of solid potassium hydroxide (KOH) are dissolved in enough distilled water to give 100 mL of solution in a coffee-cup calorimeter, the temperature of the liquid increases from 23.0°C to 34.7°C. Based on this observation, is the dissolution of KOH in water an endothermic or exothermic reaction?