1. A is a solution of potassium tetraoxomanganate (VII). B is a solution of iron (II) Chloride containing 4.80 g of the salt in 250cm3 of solution. (a) Put A into the burette. Pipette 20.0cm3 or 25.0 of B into a conical flask, add 20.0cm3 of H2SO4(aq)and titrate with A. repeat the titration to obtain concordant titire values. Tabulate your results and calculate the average volume of A used. The equation of the reaction is: MnO–4(aq) + 5Fe2+(aq) + 8H+(aq) > Mn2+(aq) + 5Fe3+(aq) + 4H2O(I)
(b) From your results and the information provided, calculate the (i) concentration of B in moldm-3; (ii) Concentration of A in moldm-3(iii) number of moles of Fe2+ in the volume of B pipetted [FeCI2 = 127 gmol-1] Credit will be given for strict adherence to the illustrations for observations precisely and for accurate inferences. all tests, observations and inferences must be clearly entered in the booklet in ink at the time they are made.
2. C and D are inorganic salts. Carry out the following exercises on them. Record your observations and identify any gas(es) evolved. State the conclusions and draw fromt the result of each test. (a) Put all of C in a test tube and add about 5cm3 of distilled water. Shake thoroughly and test the resulting solution with litmus paper. Divide the solution into three portions. (i) To the first portion, add NaOH(aq) in drops, then in excess. (ii) To the second portion, add NH3(aq) in drops, then in excess. (iii) To the third portion, add AgNO3(aq) followed by HCI(aq) (b)(i) Put all of D in a test tube and add about 5cm3 of distilled water. Shake thoroughly and feel the test tube. (ii) To about 2cm3 of the solution, add HCI(aq).
3. State the observations that would be made when each of the following reactions are carried out in the laboratory (a) Addition of 2cm3 of bench H2SO4(aq) to 2cm3 of barrium chloride solution; (b) Addition of 2cm3 of dilute hydrochloric acid to 1 g of powered iron(II) sulphide (FeS); (c) Addition of 2cm3 of dilute hydrochloric acid to 1 g of iron filings and allowed to stand for sometime.
ANSWERS
1. Equation of the reaction: MnO–4(aq) + 5Fe2+(aq) + 8H+(aq) > Mn2+(aq) + 5Fe3+(aq) + 4H2O(I)
3c(i) When exposed to light, silver chloride decomposes into gray metallic silver and chlorine. The light sensitivity of the silver chloride and other silver halides, such as silver bromide and silver iodide, forms the b
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