Enthalpy changes and Hess's law

Question 1 of 10

In an experiment, 0.92 g of ethanol (C₂H₅OH, M = 46) was burned to heat 200 g of water. The temperature of the water rose by 13 °C. (c = 4.2 J g⁻¹ °C⁻¹) (a) Calculate the heat absorbed by the water. (b) Calculate the moles of ethanol burned. (c) Calculate the enthalpy of combustion of ethanol. (d) Give two reasons why the value is less than the data-book value of −1,367 kJ/mol.

Question 2 of 10

Heat absorbed when 50 g of water warms by 4 °C (c = 4.2 J g⁻¹ °C⁻¹) is ___ J.

Question 3 of 10

An exothermic reaction

Question 4 of 10

Photosynthesis is an endothermic process.

Question 5 of 10

The enthalpy of neutralisation of a strong acid by a strong base is about

Question 6 of 10

Given A → B, ΔH₁ = −286 kJ, and B → C, ΔH₂ = −890 kJ, find ΔH for A → C.

Question 7 of 10

Combustion reactions are exothermic.

Question 8 of 10

The dissolution of ammonium nitrate in water is

Question 9 of 10

In an endothermic reaction, the products have less energy than the reactants.

Question 10 of 10

Heat absorbed when 200 g of water warms by 2 °C (c = 4.2 J g⁻¹ °C⁻¹) is ___ J.