Get premium membership and access questions with answers, video lessons as well as revision papers.
- Explain why iron nails rust faster in sodium chloride solution than in tap water.(Solved)
Explain why iron nails rust faster in sodium chloride solution than in tap water.
Date posted: September 18, 2019. Answers (1)
- Given the following reagents; solid sodium carbonate, solid lead (II) nitrate, water. Describe how a sample of lead (II) carbonate can be prepared in the...(Solved)
Given the following reagents; solid sodium carbonate, solid lead (II) nitrate, water. Describe how a sample of lead (II) carbonate can be prepared in the laboratory.
Date posted: September 18, 2019. Answers (1)
- Radioactive polonium - 216 decays as shown below.(Solved)
Radioactive polonium - 216 decays as shown below.
Date posted: September 18, 2019. Answers (1)
- Given the following polymer, draw the structure of the monomer.(Solved)
Given the following polymer, draw the structure of the monomer.
Date posted: September 18, 2019. Answers (1)
- Give the IUPAC names of the following compounds(Solved)
Give the IUPAC names of the following compounds
i) CH3(CH2)OH
ii) CU3CH2CH(CH3)COOH
Date posted: September 18, 2019. Answers (1)
- Two elements X and Y are represented as shown below(Solved)
Two elements X and Y are represented as shown below
17X and 20Y
i) Write the formula of the compound formed when X and Y react.
ii) State the family name to which element X belongs.
iii) Element Y has a mass number of 40, how many neutrons are present in its nucleus?
Date posted: September 18, 2019. Answers (1)
- Sodium hydroxide can be prepared through the following methods: I and II.(Solved)
Sodium hydroxide can be prepared through the following methods: I and II.
a) Name one precaution that needs to be taken in method I.
b) Give the name of process A.
c) Describe the chemical test of hydrogen gas.
Date posted: September 18, 2019. Answers (1)
- Describe how a student can determine the purity of tap water in a school laboratory.(Solved)
Describe how a student can determine the purity of tap water in a school laboratory
Date posted: September 18, 2019. Answers (1)
- Study the flow chart below and answer the questions that follow.(Solved)
Study the flow chart below and answer the questions that follow.
(a) Name the substance
(i) A
(ii) B
(b) State the property of S02 exhibited in step 2.
Date posted: September 18, 2019. Answers (1)
- Ethanol has a molar heat of combustion of -1360kJmol-1. Calculate the heating value of ethanol. (C=12,H=1,O=16(Solved)
Ethanol has a molar heat of combustion of -1360kJmol-1. Calculate the heating value of ethanol. (C=12,H=1,O=16
Date posted: September 18, 2019. Answers (1)
- A volume of 10cm3 of ethene gas (C2H4) was exploded with 50cm3 of oxygen.
(i) Write the equation of the reaction for the combustion of ethene.
(ii)...(Solved)
A volume of 10cm3 of ethene gas (C2H4) was exploded with 50cm3 of oxygen.
(i) Write the equation of the reaction for the combustion of ethene.
(ii) Calculate the volume of gaseous mixture.
Date posted: September 18, 2019. Answers (1)
- Both molten sodium chloride and molten sodium metal conducts electricity. Explain how each of these conducts electricity
(i) Molten sodium chloride
(ii) Molten sodium metal(Solved)
Both molten sodium chloride and molten sodium metal conducts electricity. Explain how each of these conducts electricity
(i) Molten sodium chloride
(ii) Molten sodium metal
Date posted: September 18, 2019. Answers (1)
- During the electrolysis, a current of 2 amperes was passed through the copper (II) sulphate solution for 4 hours. Calculate the volume of the gas...(Solved)
During the electrolysis, a current of 2 amperes was passed through the copper (II) sulphate solution for 4 hours. Calculate the volume of the gas produced at the anode. (1 F= 96500 C, MGV = 24000cm3).
Date posted: September 18, 2019. Answers (1)
- The solubility of iron (II) sulphate at 22oC is 15.65g/100g of water. Calculate the mass of iron (II) sulphate crystals in 90g of saturated iron...(Solved)
The solubility of iron (II) sulphate at 22oC is 15.65g/100g of water. Calculate the mass of iron (II) sulphate crystals in 90g of saturated iron (II) sulphate solution.
Date posted: September 18, 2019. Answers (1)
- Use the following information to answer the questions that follow.(Solved)
Use the following information to answer the questions that follow.
a) Draw an energy cycle diagram and label the various heat changes.
b) Use the energy circle above to calculate heat of formation of methanol.
Date posted: September 18, 2019. Answers (1)
- Differentiate between a monomer and polymer.(Solved)
Differentiate between a monomer and polymer.
Date posted: September 18, 2019. Answers (1)
- Pentanoic acid reacts with butan – 1 – 0l to form an organic compound.(Solved)
Pentanoic acid reacts with butan – 1 – 0l to form an organic compound.
(i) Write an equation to show the above reaction.
(ii) What is the name given to the above type of reaction?
(iii) A few drops of a certain catalyst must be added to the mixture to increase the rate of the reaction.
(a) Name the catalyst.
(b) Explain the role of the catalyst in the above reaction.
Date posted: September 18, 2019. Answers (1)
- Two methods of preparing alkenes are shown by the following general equations.(Solved)
Two methods of preparing alkenes are shown by the following general equations.
(a) What type of reactions are described by equations;
(i)and (ii)
(b) Which of the two methods is used on a large scale.
Date posted: September 18, 2019. Answers (1)
- Draw the structural formula of the following compounds:-
(i) 2 – melthylhex –l-ene
(ii) Butan –l-ol(Solved)
Draw the structural formula of the following compounds:-
(i) 2 – melthylhex –l-ene
(ii) Butan –l-ol
Date posted: September 18, 2019. Answers (1)
- You are provided with the following electrode potentials of four half-cell reactions. Letters do not represent the actual symbol of the element(Solved)
You are provided with the following electrode potentials of four half-cell reactions. Letters do not represent the actual symbol of the element
(a) Identify the strongest reducing agent. Explain.
(b) Calculate the emf of the two half cells that when combined would produce the largest emf.
Date posted: September 17, 2019. Answers (1)