Classwork For Senior Secondary School Students

CLASSWORK

SSS 2 CHEMISTRY

1ai. Explain why water is referred to as universal solvent (ii) Give one chemical test for water

1b. Describe in outline the purification of water for town supply

1ci. Give a reason why a given mass of sodium hydroxide pellets cannot be used to prepare a standard solution

cii. Define the following terms and give two examples in each case: (I) Efflorescence   (II) Deliquescence    (III) Hygroscopy

2ai. State two physical properties of chlorine (ii) Write equations to show how chlorine reacts with: (I) Iron(ii)chloride   (II) Dilute sodium hydroxide

2b. Explain why chlorine is preferred to sulphur(iv)oxide in the bleaching of cotton

2c. Baking soda and hydrochloric acid react according to the following equation:                     NaHCO_3(aq) +  HCl ----- -> NaCl   +  CO₂  +  H₂O. Calculate the mass of baking soda that would produce 10g of CO_2. [H = 1, O = 16, C = 12, Na = 23]

SSS 3 CHEMISTRY

1ai. Balance the following redox equation: MnO₄^- +  C₂O₄^2-  ------> Mn²⁺ +  CO₂

aii. From the equation, name the specie that is (I) Reduced with reason  (II) a Reducing agent with reason.

iii. Mention one observation made in the equation    (iv) How many moles of electrons are transferred in the balanced equation.

bi How would you determine the end point of titration involving the above reaction

bii. In terme of electron transfer, define oxidation and oxidizing agent

2ai. State two similarities between reaction of sodium with water and that of sodium with ethanol

aii. What happens when ammonia gas is bubbled through ethyl ethanoate.

bi. Define the term polymerization (ii) List the three conditions required for polymerization of ethene

iii. State the property which is common to compounds that can be easily polymerized.

iv. List two factors which affects the strength of a polymer

bi. Write appropriate equations to show how the following can be obtained from propan-1-ol in laboratory

  (I) Propene (II) Propylmethanoate. State the type of reaction involved in each case

c. A compound contains 40% carbon, 6.7% hydrogen and 53.3% oxygen. Determine its molecular formula if its molar mass is 180 (H = 1, O = 16, C = 12)