CIE Chemistry (US-0439): Specimen Questions with Answers 69 - 71 of 240

Question number: 69

MCQ▾

Question

Which substance does not require oxygen in order to produce energy?

Choices

Choice (4) Response

a.

Coal

b.

Hydrogen

c.

Natural gas

d.

Answer

d.

Explanation

Correct option is D i. e. because uranium do not require oxygen to produce energy in a nuclear reactor the uranium fuel is assembled in such a way that a controlled fission chain reaction can be achieved. The heat created by splitting the atoms is then used to make steam which spins a turbine to drive a generator, producing electricity. And when we try to produce energy from coal, hydrogen, and natural gas it require oxygen.

Question number: 70

Short Answer Question▾

Write in Short

Aluminum is used to make high voltage electricity cables.

details of four metals

Details of Four Metals

details of four metals

The table shows some properties of four metals which could be used for overhead power cables.

overhead power cables.

Overhead Power Cables.

overhead power cables.

Suggest why steel, rather than copper, is used as a core for overhead power cables.

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

Explanation

Steel rather than copper is used as a core for overhead power cables because steel has less electrical conductivity than copper.

Question number: 71

Short Answer Question▾

Write in Short

The table shows some physical properties of the Group VII elements.

some physical properties of the Group VII elements

Some Physical Properties of the Group VII Elements

some physical properties of the Group VII elements

Use the information in the table to explain why

bromine is a liquid at room temperature. ………………………………………………………….

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

Explanation

Bromine is a liquid because the intermolecular forces are strong enough so that it does not vapourise. Br forms diatomic molecules and van der Waals interactions are sufficiently strong.