WAEC GCE 2017 Chemistry Expo Answers, West Africa Examination Council, November/December GCE Maths Expo Answers For Free.
No1b)Metals are good reducing agent because the are electro donors (metal ionizes by loss of electron)
1c) i) Diamond is used in jewelry because they resist chemical attack and high temperature.
ii) Diamond is used as abrassive because they are dense and hard.
iii) Diamond is a non conductor of electricity because they lack free valence electron
No1di) Chemical change: this is a change which is irreversible and new substances are formed. They are mainly in form of chemical reaction.
(1dii)example of chemical change.
(I)rusting of iron
(II)reaction of acid and Base to form salt and water
(No1e)isotope: these are elements with the same atomic number but different mass number or atomic mass.
(No1f) a weak acid is a substance which does not ionize or dissociate completely in solution. While a dilute acid is an acid with lower concentration, a dilute acid is formed when water is added to concentrated acid
(1g) PH: this is the negative logarithm to the base ten(10) of hydrogen concentration
(1h) 1. It causes formation of acid rain
2. It causes photochemical smog and ozone layer depletion
(1i) Cl2 + Mgbr2 -> MgCl2 + Br2
(1fi) By simple diffusion
(1fii) Oxidation of the ethanol can be prevented by the removal of oxidizing agent such as Kmno4 or K2Cr2 or by the addition of lithium tetrahydrido aluminate(iii)
By - Ajayi Amos,
At - 5:10 pm.
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