Enthalpy

The thermite reaction, the reaction between aluminum and iron (III) oxide, produces a tremendous amount of heat: 2Al(s) + Fe2O3(s) → Al2O3(s) + 2Fe(s) + 852 kJ/mol If you begin with 30.0 g of Al and excess Fe2O3, how many kilojoules of heat are evolved at constant pressure?

• 1,787.7 kJ

• 546.75 kJ

• 947.25 kJ

• 1,250.25 kJ

Calculate the heat absorbed by 105.0 grams of water when it is heated to cook spaghetti. The initial temperature of the water is 20.0°C, and the final temperature of the water is 99.0°C. The specific heat of water is 4.18 J/g•°C.

• 8778 J/g°C
• 0.0005 J/g°C
• 34673 J/g°C
• 43451.1 J/g°C

ΔH means:

• temperature

• calorimetry

• enthalpy

• syntropy

If ΔH is positive, heat would be shown on the _____ side of the thermochemical equation.

• Reactant

• Product

Calculate ΔH when 2 moles of ethanol (C₂H₅OH) reacts with excess oxygen according to the following thermochemical equation?

C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O ΔH = −1366.7 kJ

• -2733.4 kJ

• -683.35 kJ

• -1366.7 kJ

• -910.67 kJ

What is ΔH if 2 mol of O₂(g) is reacted in this reaction?

H₂(g) + ½ O₂(g) → H₂O(l) ∆H = -285.8 kJ

• -570 kJ

• -71.45 kJ

• -1143.2 kJ

• -142.9 kJ