CIE Chemistry (US-0439): Specimen Questions with Answers 33 - 35 of 240

Question number: 33

Short Answer Question▾

Write in Short

What is meant by the term enzyme?

……………………………………………………………………………………………………………………………………………………………………………………………………………………

Explanation

Enzymes are macro molecular biological catalysts. Enzymes accelerate chemical reactions. The molecules upon which enzymes may act are called substrates and the enzyme converts the substrates into different molecules known as products.

Question number: 34

MCQ▾

Question

For proper collection and disposal of domestic sewage, which one of the following practices cannot be followed?

Choices

Choice (4) Response

a.

Wastes should be segregated before disposal.

b.

Separate septic tanks should be used by each house.

c.

Rivers and lakes should be used for washing purposes.

d.

Wastes should be deposited at designated places.

Answer

c.

Explanation

For proper collection and disposal of domestic sewage, rivers and lakes should not be used for washing purposes as it leads to water pollution.

Question number: 35

Short Answer Question▾

Write in Short

The diagram shows an electrolysis circuit.

At which electrode is hydrogen formed?

Image of electrolysis circuit

Image of Electrolysis Circuit

Image of electrolysis circuit

Explanation

Correct Answer is A because only aqueous sodium chloride solution takes place in electrolysis and produce ions. The water reaction would have produced H+ ions though, making the water acidic at the anode. The indicator didn’t change to the acid color, it just turned the color of bleach. When you bubble Chlorine through water, you get the Hypochlorite ion through. At the cathode where the reduction of water occurred (favored over the reduction of Na+ As shown in figure.