Measuring enthalpy changes

Which classification is correct for this reaction? $\ce{2Mg(s) + CO2(g) -> 2MgO(s) + C(s)}$, heat is released A. Endothermic; temperature decreases; reactants more stable B. Exothermic; temperature decreases; products more stable C. Exothermic; temperature…

In aqueous solution hydrogen cyanide behaves as a weak acid. (i) Write an equation for the ionization of hydrogen cyanide in water. (ii) Outline two ways in which a solution of 0.050 $\mathrm{mol\,dm^{-3}}$ $\ce{HCN}$ could be distinguished experimentally from…

The sealed vessel was left for the reaction to proceed. Suggest two properties of the system, other than its colour, that could be measured to follow the progress of the reaction over time, and predict how each would change as the forward reaction proceeds.

Suppose carbonyl dibromide were made by a free-radical chain reaction of carbon monoxide, $\ce{CO}$, with bromine vapour, $\ce{Br2}$, started by ultraviolet light. The questions below treat this hypothetical route with the bond-enthalpy model and the entropy…

Calculate the rise in temperature of 400.0 $\mathrm{cm^3}$ of water heated by the complete combustion of 2.00 g of butan-1-ol, assuming that all the energy released is transferred to the water. Use sections 2 and 14 of the data booklet.

The energy profile below was recorded for a reaction. Which pair of statements is consistent with it? In each option the first statement compares the enthalpy of the products with that of the reactants and the second gives the sign of $\Delta H$. A. products…

A liquid fuel was burned in a spirit burner and the heat released was used to warm water in a metal calorimeter, as shown. Quantity Value Amount of fuel burned 0.0250 mol Mass of water 150 g Initial temperature of water 19.5 °C Final temperature of water 31.5…

Which row correctly describes an endothermic reaction? A. The temperature of the surroundings rises and the products are more stable than the reactants. B. The temperature of the surroundings falls and the products are more stable than the reactants. C. The…

When 0.601 g of propan-1-ol is burned, the heat released raises the temperature of 250 $\mathrm{cm^3}$ of water by 8.00 K. What is the enthalpy of combustion of propan-1-ol, in $\mathrm{kJ\,mol^{-1}}$, calculated from these results? Specific heat capacity of…

A student stirred 0.030 mol of solid sodium hydrogencarbonate into 40 $\mathrm{cm^3}$ of a 1.0 $\mathrm{mol\,dm^{-3}}$ solution of ethanedioic acid. $\ce{H2C2O4(aq) + 2NaHCO3(s) -> Na2C2O4(aq) + 2CO2(g) + 2H2O(l)}$ The temperature of the solution fell from…