CIE Chemistry (US-0439): Specimen Questions with Answers 9 - 12 of 240

Question number: 9

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All metal nitrates decompose when heated. A few form a nitrite and oxygen. Most form the metal oxide, oxygen and a brown gas called nitrogen dioxide.

Almost all samples of nitrogen dioxide are an equilibrium mixture of nitrogen dioxide, NO2, and dinitrogen tetroxide, .

Explanation

In the forward reaction, a bond forms between the two nitrogen dioxide molecules.

Question number: 10

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Iron from the blast furnace is impure. It contains 5 % of impurities, mainly carbon, sulfur, silicon and phosphorus. Almost all of this impure iron is converted into the alloy, mild steel.

use [2 Marks]

Explanation

It is used in the production of non-ferrous alloys (12%), alloy steels (5%), plating (7%), foundry (3%) and batteries (2%).

Question number: 11

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Answer the following questions about these structures. Each structure can be used once, more than once or not at all.

structures of five atoms

Structures of Five Atoms

structures of five atoms

Which two structures are hydrogen atoms? …………. and ………….

Explanation

Correct option is A and E because hydrogen have one electron in its outer most shell or valence shell.

Question number: 12

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Ethanoic acid can be used as a solvent. What is the meaning of the term solvent? ………………………………………………………………………………………………. [1]

Explanation

A solvent is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a super critical fluid. Here solvent is Ethanoic acid.