Energetics Assessment

In an investigation the following setup was used. What was the student investigating?

• Enthalpy change of combustion
• Enthalpy change of neutralisation
• Enthalpy change of displacement

Which is the most significant source of error when conducting the investigation?

• The thermometer is misread
• The can does not conduct heat efficiently
• The heat from the combustion reaction heats the surroundings as well as the can
• The amount of fuel combusted can vary because it always evaporates rapidly.

Calculate the RFM of methane CH₄

• 10
• 11
• 14
• 16

Calculate the RFM of butane C₄H₁₀

• 1
• 34
• 58
• 116

Calculate the number of moles of 1g of methane CH₄

• 0.10
• 0.083
• 0.071
• 0.063

Calculate the number of moles in 32g of sulfuric acid

• 0.16
• 0.22
• 0.33
• 0.64

Calculate the number of moles in 2g of sodium hydroxide

• 0.05
• 0.10
• 0.15
• 0.20

In an experiment, 0.600 g of propane (C₃H₈) was completely burned in air. The heat evolved raised the temperature of 100 g of water by 64.9°C. Calculate the heat energy released (Q) in joules, using the specific heat capacity of water as 4.18 J/ g K.

• 27128.2 J
• 27.1282 kJ
• 162.77 J
• 0.16277 kJ

50 cm³ of 1.0 mol/dm³ hydrochloric acid was added to 50 cm³ of 1.0 mol/dm³ sodium hydroxide solution. The temperature rose by 6.8°C. Calculate the heat energy released from this reaction (Q) in joules, using the specific heat capacity of the solution as 4.18 J / g K.

• 1421.2 J
• 1.4212 kJ
• 2842.4 J
• 2.8424 kJ

100 cm³ of 0.200 mol/dm³ copper sulfate solution was put in a calorimeter and an excess magnesium powder added. The temperature of the solution rose by 25.1°C, the specific heat capacity of the solution is 4.18 J / g K. Calculate the enthalpy change per mole of copper sulfate.

• -175 kJ/mol
• -350 kJ/mol
• -525 kJ/mol
• -1050 kJ/mol