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- The scheme below shows the energy changes that take place between ice, water and steam.
Study it and answer the questions that follow:-(Solved)
The scheme below shows the energy changes that take place between ice, water and steam.
Study it and answer the questions that follow:-
(a) What name is given to the energy change 
(b) What is the sign 
give a reason
Date posted: October 28, 2019. Answers (1)
- Study the diagram below and answer the questions that follow:(Solved)
Study the diagram below and answer the questions that follow:
Date posted: October 28, 2019. Answers (1)
- Iodine can react with chlorine as shown below:-(Solved)
Iodine can react with chlorine as shown below:-
Determine the molar enthalpy change for this reaction
Date posted: October 28, 2019. Answers (1)
- The equation below represents changes in the physical state of ions metal:(Solved)
The equation below represents changes in the physical state of ions metal:
Calculate the amount of heat energy required to change 10kg of solid iron to gaseous iron
Fe = 56
Date posted: October 28, 2019. Answers (1)
- The setup below was used to investigate the changes that take place when sodium hydroxide pellets dissolve in water.(Solved)
The setup below was used to investigate the changes that take place when sodium hydroxide pellets dissolve in water.
a) Why is a plastic beaker used instead of a metallic beaker?
b) State and explain the observations made in the above reaction
Date posted: October 28, 2019. Answers (1)
- Calculate the latent heat of vaporization of water
H2O(l)-------->H2O(g)(Solved)
Calculate the latent heat of vaporization of water
H2O(l)-------->H2O(g)
Given the following thermo chemical equations:-
Date posted: October 28, 2019. Answers (1)
- The rise in temperature when 50cm3 of sodium hydroxide is reacted with two acids is given
in the table below:-(Solved)
The rise in temperature when 50cm3 of sodium hydroxide is reacted with two acids is given
in the table below:-
Explain the difference in the temperature.
Date posted: October 28, 2019. Answers (1)
- Turning of fossil fuels has adverse environmental effects:-
a) Name two pollutants from the burning of petroleum products
b) Give one precaution taken to minimise the pollution...(Solved)
Turning of fossil fuels has adverse environmental effects:-
a) Name two pollutants from the burning of petroleum products
b) Give one precaution taken to minimise the pollution by fossil fuels
Date posted: October 28, 2019. Answers (1)
- Consider the following equilibrium reaction.(Solved)
Consider the following equilibrium reaction.
State and explain the effect of formation of hydrogen chloride if pressure was increased in the equation above
Date posted: October 28, 2019. Answers (1)
- Biogas is a mixture of mainly Carbon (IV) Oxide and methane.
(i) Give a reason why biogas can be used as a fuel
(ii) Other than fractional...(Solved)
Biogas is a mixture of mainly Carbon (IV) Oxide and methane.
(i) Give a reason why biogas can be used as a fuel
(ii) Other than fractional distillation, describe a method that can be used to determine the percentage of methane in biogas
Date posted: October 28, 2019. Answers (1)
- A typical electrolysis cell uses a current of 40,000 amperes. Calculate the mass (in Kg of aluminium produced in one hour). (Al = 27) (Faraday...(Solved)
A typical electrolysis cell uses a current of 40,000 amperes. Calculate the mass (in Kg of aluminium produced in one hour). (Al = 27) (Faraday = 96500 Coloumbs)
Date posted: October 28, 2019. Answers (1)
- Distinguish between molar latent heat of fusion and molar latent heat of vaporization(Solved)
Distinguish between molar latent heat of fusion and molar latent heat of vaporization
Date posted: October 28, 2019. Answers (1)
- Study the graph below and answer the questions which follow:(Solved)
Study the graph below and answer the questions which follow:
Explain the changes occurring between points BC and CD
Date posted: October 28, 2019. Answers (1)
- The grid below shows part of the periodic table. Use it to answer the questions that follow. The letters are not the actual symbols.(Solved)
The grid below shows part of the periodic table. Use it to answer the questions that follow. The letters are not the actual symbols.
i) Write the equation for the reaction that occurs between elements L and D
ii) The oxide of G reacts with both hydrochloric acid and sodium hydroxide. What is the nature of
the oxide of G?
iii) Explain why elements H has a higher boiling points than element D.
iv) State one use of element E
v) Compare and explain the atomic radius of B and C
vi) 11.5g of L was completely burnt in oxygen .Calculate the volume of gas that was used.
(L = 23, molar gas volume at room temperature is 24dm3)
Date posted: October 28, 2019. Answers (1)
- Sodium hydrogen carbonate was strongly heated.
Write an equation for the reaction(Solved)
Sodium hydrogen carbonate was strongly heated.
Write an equation for the reaction
Date posted: October 28, 2019. Answers (1)
- When 1.6g of ammonium nitrate were dissolved in 100cm3 of water, the temperature dropped by 6ºC. Calculate its enthalpy change. (Density of water = 1g/cm3,specific...(Solved)
When 1.6g of ammonium nitrate were dissolved in 100cm3 of water, the temperature dropped by 6ºC. Calculate its enthalpy change. (Density of water = 1g/cm3,specific heat capacity is 4.2kJ kg-1K-1)
Date posted: October 28, 2019. Answers (1)
- Bond energies for some bonds are tabulated below:-(Solved)
Bond energies for some bonds are tabulated below:-
Use the bond energies to estimate the enthalpy for the reaction
C2H4(g) + H2(g)----->C2H6(g)
Date posted: October 28, 2019. Answers (1)
- Study the table below and answer the questions that follow(Solved)
Study the table below and answer the questions that follow
a) Calculate the enthalpy change for the following reaction
C2H4(g) + Br2(g)------->C2H4Br2(g)
b) Name the type of reaction that took place in (a) above
Date posted: October 28, 2019. Answers (1)
- Nitrogen and hydrogen react reversibly according to the equation:-(Solved)
Nitrogen and hydrogen react reversibly according to the equation:-
The energy level diagram for the above reaction is shown below:-
(a) How would the yield of ammonia be affected by:
(i) A decrease in temperature
(ii) An increase in pressure
(b) How does a catalyst affect reversible reaction already in equilibrium?
(c) On the above diagram, sketch the energy level diagram that would be obtained when iron catalyst is added to the reaction
Date posted: October 28, 2019. Answers (1)
- Using the heats of combustion of the following substances, calculate the heat of formation of ethanol(Solved)
Using the heats of combustion of the following substances, calculate the heat of formation of ethanol
Date posted: October 28, 2019. Answers (1)