WAEC Questions and Answers on Chemistry for 2019

WAEC Questions and Answers on Chemistry for 2019-Getting ready for WAEC Examination? here are few questions to expect in the forthcoming WAEC Examination. WAEC Examination is one one where questions are always repeated, you can get absolutely great scores if you’re on track with the best possible questions,get them and study repeatedly to guarantee absolute success.

Here there are in no particular order…..WAEC Questions and Answers on Chemistry for 2019/2020 and the most likely repeated questions to expect

WAEC Questions and Answers on Chemistry for 2019OBJECTIVE

1.       Which of the following acids forms normal salts only? (a) tetroxosulphate (vi) acid   (b) trioxosulphate (iv) acid   (c) tetroxophophate (v) acid (d) trioxonitriate (v) acid

2.       A substance is said to be hygroscopic if it absorbs;

(a) water from the atmosphere to form a solution (b) heat from the surrounding  (c) carbon (iv) oxide from the atmosphere (d) moisture from the atmosphere without dissolving

3.       Which of the following salt solutions will have a pH greater than 7?

(a) NaCl (b) Na2CO3 (c) Na2S04 (d) NaHSO4

4.       One of the methods used for combating air pollution is:

(a) burning of solid waste (b) provision of sanitary land fills

(c) legislation against some industrial practices (d) scavenging of refuse dumps

5.       Which of the following is correct about solution of pH 4 is correct?

(a) addition of NaOH will decrease its pH       (b) it will turn red litmus blue (c)  it is less acidic than a solution of pH 2 (d) its hydrogen ion concentration is 10-4 moldm-3

6.       Concentrated H2SO4 is a good drying agent for most gases because it is   (a) hygroscopic (b) dibasic (c) corrosive      (d) oxidizing

7.       What is the deposit formed on boiling water that contains temporary hardness

(a) magnesium tetraovosulphate (vi)   (b) calcium trioxocarbonate (iv)   (c) magnesium hydrogen trioxocarbonate (iv)   (d) calcium tetroxosulphate (vi)

8.       When a sample of water was boiled it lathered more readily with soap. It can be concluded that the sample most likely contained

          (a) magnesium tetraoxosulphate (vi)          (b) suspended solids (c) organic impurities (d) calcium hydrogentrioxocarbonate (iv)

9.       What are the two gases associated with acid rain?         

(a) CO2 and HCl (b) CO2 and N2 (c) SO2 and NO2 (d) HCL and SO2

10.     What are the values of x, y and z respectively in the following equation?

          MnO2 + xHCl           MnCl2 + yH2O + zCl2

(a) 4, 1, 2 (b) 1, 2, 1 (c) 2, 1, 2 (d) 4, 2, 1

11.     Which of the following pollutants is biodegradable?

(a) domestic sewage (b) metal scraps   (c) radioactive waste       (d) plastic foil

12.     Which of the following substances is hygroscopic in nature?

          (a) CaCl2 (b) CuO (c) MgCl2

(d) Na2CO3.10H2O (d) P2O10

13.     Sour milk contains   acid (a) citric (b) ethanoic (c) lactic (d) methanoic

14.     A salt that absorbs moisture from the atmosphere without forming a solution is said to be

(a) efflorescent (b) deliquescent                 (c) hygroscopic (d) insoluble

15.     What process is involved in the reaction represented by the following equation?        

          AlCl3 + 3H2O        Al(OH)3 + 3HCl (a) dehydration (b) hydrolysis (c) double decomposition  (d) neutralization

16.     Consider the reaction represented by the equation below:

          xNH3 + yCl2          zHCl + N2

          The values of x, y and z are respectively

          (a) 2, 4, 6 (b) 3, 2, 4 (c) 2, 3, 6 (d) 3, 2, 6  

17.     Hardness in water can be removed by adding

          (a) copper (II) tetraoxosulphate (VI)  (b) sodium trioxocarbonate (IV) (c) sodium chloride (d) alum

18.     X and Y form a salt in which X is a trivalent cation and Y is a bivalent anion. Which of the following equations represents the dissociation of the salt?

(a) XY        X3+ + Y2-

(b) X3Y2        3X+  + Y2-

(c) X2Y3           2X3+ + 3Y2-                 

(d) X2Y2         2X3+ + 2Y2-

19.     N  is formed form NH3 and H+ by

(a) covalent bonding (b) dative bonding      (c) hydrogen bonding   (d) ionic bonding 

20.     The purity of a solid sample can best be determined by its:

(a) boiling point (b) melting point   (c) conductivity (d) solubility

21.     The separation of petroleum fraction depends on the difference in their (a) melting point (b) molar masses   (c) solubilities (d) boiling point

22.     Which of the following bond types is responsible for the high boiling point of water?

(a) metallic bond (b) covalent bond (c) ionic bond (d) hydrogen bond

23.     Which of the following elements is diatomic? (a) sodium (b) oxygen (c) iron (d) neon

24.     An atom of an element X gains two electrons. The symbol of the ion formed is?  (a) X+ (b) X2+ (c) X2- (d) X

25.     On heating, the following trioxocarbonate (iv) salts decompose to give solid residue except  (a) ammonium trioxocarbonate (iv)            (b) calcium trioxocarbonate (iv) (c) lead trioxocarbonate (iv) (d) zinc trioxocarbonate (iv)

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Check Mostly Repeated CHEMISTRY WAEC Examination questions (2ND ) PART HERE