Welcome to the Quiz!
This quiz contains 13 questions from a mix of 1 subtopics.
Select the correct equation for enthalpy change, ΔH.
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Select the correct equation for energy change, q.
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What are the units of specific heat capacity?
J g-1 K-1
J-1 g-1 K
J g K
J-1 g K-1
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Which equation represents the enthalpy change of combustion of methanol, CH3OH?
CH3OH + 3⁄2O2 ➔ CO2 + 2H2O
CH3OH + 2O2 ➔ CO2 + 2H2O
2CH3OH + 5⁄2O2 ➔ 2CO2 + 2H2O
2CH3OH + 3O2 ➔ 2CO2 + 2H2O
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The enthalpy change of combustion, ΔHc, of ethanol, C2H5OH, was determined by calorimetry:
C2H5OH(l) + 3O2(g) ➔ 2CO2(g) + 3H2O(l)
0.460 g of ethanol was burnt and the temperature of 200 g of water rose by 7.00 K.
Calulate ΔHc of ethanol. Give your answer to 3 significant figures.
The specific heat capacity, c, of water is 4.18 J g-1 K-1.
kJ mol-1
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List three possible reasons why the experimental value of ΔHc for methanol is less exothermic than the data book value.
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What is the main purpose of using plastic cups made of polystyrene foam in enthalpy change experiments?
to make the reaction faster
to provide insulation against heat loss
to reduce the cost of the experiment
to increase the accuracy of temperature measurements
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What is the energy change, in kJ, for a 50.0 g of water that decreases in temperature from 20°C to 10°C?
The specific heat capacity of water is 4.18 J g-1 K-1.
-2,090 kJ
-209 kJ
-20.9 kJ
-2.09 kJ
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What is the purpose of a cooling curve correction in enthalpy change experiments?
to calculate the density of the mixture
to measure the specific heat capacity of the solution
to account for heat loss during the cooling phase
to determine the maximum temperature of the reaction
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Give two advantages of using plastic cups made of polystyrene foam in enthalpy change experiments.
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The enthalpy change of neutralisation, ΔHneut, of HCl by NaOH was determined experimentally:
HCl(aq) + NaOH(aq) ➔ NaCl(aq) + H2O(l)
When 25.0 cm3 of 1.60 mol dm-3 of HCl was mixed with 25.0 cm3 of 1.60 mol dm-3 of NaOH, the temperature rose by 14.0°C.
Calulate ΔHneut of the reaction. Give your answer to 3 significant figures.
The specific heat capacity, c, of the mixture is 4.18 J g-1 K-1.
Assume the density of both solutions is 1 g cm-3.
kJ mol-1
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What mass of water, in g, was used in a calorimetry experiment if 8.78 kJ of energy is transferred to the water and its temperature increased from 20°C to 32°C?
The specific heat capacity of water is 4.18 J g-1 K-1.
125 g
150 g
175 g
200 g
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What was the starting temperature, in °C, of the water in a calorimetry experiment if 10.0 kJ of energy is transferred to 150 g of water and its final temperature was 43°C?
The specific heat capacity of water is 4.18 J g-1 K-1.
16°C
27°C
33°C
59°C
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