Water - Chemistry Jamb Past Questions and Answers

Question 31 :

• JAMB 1994

which of these metals CANNOT replace hydrogen from alkaline solutions?

A. Aluminium
B. Zinc
C. Tin
D. Iron

Question 32 :

• JAMB 1994

Clothes should be properly rinsed with water after bleaching because

A. The bleach decolourizes the clothes
B. Chlorine reacts with fabrics during bleaching
C. The clothes are sterilized during bleaching
D. Hydrogen chloride solution is produced during bleaching

Question 33 :

• JAMB 1997

On recrystallization, 20g of magnesium tetraoxosuphate (IV) forms 41 g of magnesium tetraoxosulphate (IV) crystals, MgSO₄. yH₂O. The value of y is?
(Mg = 24, S = 32, O = 16, H = 1)

A. 1
B. 3
C. 5
D. 7

Question 34 :

• JAMB 1997

A major process involved in the softening of hard water is the?

A. Conversation of a soluble calcium salt to its trioxoncarbonate (lV)
B. Decomposition of calcium rioxocarbonate (lV)
C. Conversion of an insoluble calcium salts to its trioxocarbonate (lV)
D. Oxidation of calcium atoms to its ions

Question 35 :

• JAMB 1997

The synthetic detergents are preferred to soap for laundry using hard water because?

A. Detergents are water soluble while soap is not
B. The calcium salts of detergents are water soluble
C. The magnesium salt of soap is soluble in hard water
D. Soap does not have a hydrocarbon terminal chain