Worksheetsheat of combustion
Total questions: 10
Worksheet time: 18mins
The table shows the heat of combustion of three alcohols.
Which of the following factors increases the heat of combustion of alcohols?
Size of molecules decreases
Number of carbon atoms per molecule increases
Number of oxygen atoms per molecule increases
Number of hydrogen atoms per molecule decreases
The following equation shows the combustion of heptane, C7H16, in excess oxgen.
C7H16(l) + 11 O2(g) → 7 CO2(g) + 8 H2O ΔH= -5 512 kJ mol-
The combustion of heptane in excess oxygen releases 1 378 kJ of energy.
What is the mass of heptane used?
[relative atomic mass of H = 1 and C = 12]
25.0 g
36.0 g
77.0 g
88.0 g
The following information shows the results of an experiment to determine the heat change for the combustion of propanol, C3H7OH.
Volume of water in the copper container= 300 cm3
Initial temperature of water in copper container=27.5 °C
Highest temperature of water in copper container = 68.5 °C
What is the heat released by the combustion of propanol, C3H7OH?
[Specific heat capacity of water = 4.2 J g-1°C-1 ; Water density = 1 g cm-3]
34.65 kJ
51.66 kJ
86.3 kJ
120.96 kJ
100 cm3 of water is heated by the burning of a sample of ethanol.
The heat released by the combustion is 10.5 kJ.
What is the maximum increase in temperature of the water?
[Specific heat capacity of water = 4.2 Jg-1oC-1]
0.025°C
0.25°C
2.5°C
25°C
Diagram 14 shows an energy level diagram for propan-1-ol.
Which of the following sattement is correct about the reaction?
X kJ of heat is absorbed during the reaction.
The final temperature is lower than initial temperature.
The heat of combustion of propan-1-ol is -X kJ/mol
The total energy content of product is higher than the reactant.
The following is the energy level diagram of a reaction.
Which of the following acids is suitable to replace nitric acid, HNO3 to obtain the same ΔH value ?
Ethanoic acid, CH3COOH
Carbonic acid, H2CO3
Sulphuric acid, H2SO4
Hydrochloric acid, HCl
In an experiment, 100 cm3 of dilute hydrochloric acid solution is mixed with 100 cm3 sodium hydroxide solution in a polystyrene cup. The concentrations of the two solutions are the same. During the mixing, the temperature of the mixture increased by 7 0C.
What is the heat released in the experiment?
Given that the specific heat capacity of the solution is 4.2 J g-1 0C-1.
1470 J
2940 J
4410 J
5880 J
The reaction between 25.0 cm3 of hydrochloric acid and 25.0 cm3 of sodium hydroxide solution releases the heat of 2100 J.
What is the temperature change of the mixture?
[Specific heat capacity of a solution = 4-2 Jg ^C"1;
Assume that 1 cm3 of a solution is equal to 1 g of the solution]
1°C
2°C
10 °C
20 °C
Which process absorbs energy?
Evaporation
Combustion
Neutralisation
Displacement
Which of the following is an endothermic reaction?
HCI + NaOH → NaCl + H2O
HCI + NaHCO3 → NaCl + CO2 + H2O
NaCl + AgNO3 → AgCl + NaNO3
Zn + CuSO4 → ZnSO4 + Cu
