(i) Electroplating steel objects with silver involves a three-step process.
step 1 A coating of copper is applied to the object.
step 2 A coating of nickel is applied to the object.
step 3 The coating of silver is applied to the object.
(a) A diagram of the apparatus used for step 1 is shown.
1. The chemical process taking place on the surface of the object is Cu2+ (aq) + 2e- -> Cu(s)
What is the observation seen on the surface of the object?
2. Explain why the concentration of copper ions in the electrolyte remains constant throughout step1.
(b) Give two changes which would be needed in order to coat nickel onto the object in step 2.
(c) Write down the reaction taking place at the positive electrode during step 3.
(ii) Match the following Column A with Column B.
(iii) Complete the following by choosing the correct answers from the bracket:
(a) If an element has one electron in the outermost shell, then it is likely to have the _____ [smallest/ largest] atomic size amongst all the elements in the same period.
(b) ______ [sulphuric acid/ hydrochloric acid] does not form an acid salt.
(c) A ______ [reddish brown/ dirty green] coloured precipitate is formed when ammonium hydroxide is added to a solution of ferrous chloride.
(d) Alkynes undergo _______ [addition / substitution] reactions.
(e) An _____ [alkaline/acidic] solution will turn methyl orange solution pink or red.
(iv) Identify the following:
(a) A bond formed between two atoms by sharing of a pair of electrons, with both electrons being provided by the same atom.
(b) A salt formed by the complete neutralization of an acid by a base.
(c) A reaction in which the hydrogen of an alkane is replaced by a halogen.
(d) The energy required to remove an electron from a neutral gaseous atom.
(e) A homogenous mixture of two or more metals or a metal and a nonmetal in a definite proportion in their molten state.
(v) (a) Draw the structural diagram for the following compounds:
1. propanoic acid
2. pentan-2-ol
3. 2,2 dibromo butane
(b) Give the IUPAC name of the following organic compounds:
Solution
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