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Chemistry Past Questions and Answers

Waec Chemistry Questions

Question 1521:

During water treatment for town supply, water is passed through layers of send beds in order to

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A Soften the water
B Filter the water
C Decolorize the water
D Destroy the germs in the water
E Coagulate colloidal particles in the water

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Question 1522:

The cleansing action of soap in hard water is not satisfactory because soap

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A Forms insoluble calcium and magnesium salts
B Is made from fats and oils
C Has an organic component
D Alters the surface tension of water
E Is a sodium salt of higher carboxylic acids

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Question 1523:

What is the role of MnO₂ in the reaction represented by the following equation?MnO₂ + 4HCI₂ + CI₂ + 2H₂O

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A Bleaching agent
B Oxidizing agent
C Amphoteric oxide
D Basic oxide
E Catalyst

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Question 1524:

Nitrogen is prepared on a large scale by the

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A Fractional distillation of liquefied air
B Decomposition of ammonium dioxonitrate (lll)
C Electrolysis of brine
D Haber process
E Contact process

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Question 1525:

Ammonia gas is suitable for performing the 'Fountain' experiment because the gas is

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A Colourless
B A cooling agent
C Alkaline to litmus
D A reducing agent
E Very soluble in water

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