IGCSE Chemistry Paper-1: Specimen Questions with Answers 11 - 12 of 99

Question number: 11

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MCQ▾

Question

X is a monatomic gas. Which statement about gas X is correct?

Choices

Choice (4)

a.

X is coloured.

b.

X burns in air.

c.

X will displace iodine from potassium iodide.

d.

X is unreactive.

Answer

d.

Explanation

monatomic is a combination of the words “mono” and “atomic, ” and means “single atom. ” It is usually applied to gases: a monatomic gas is one in which atoms are not bound to each other. he noble gases are unreactive because they have a full valence shell of electrons and since they are unreactive and with a full outer shell. They don’t need to bond to themselves to fill the shell and are able to exist monoatomically.

Question number: 12

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MCQ▾

Question

The diagram shows reactions of substance Y. Find Y.

Identifying the substance Y

Identifying the Substance Y

Choices

Choice (4)

a.

an alcohol

b.

a catalyst

c.

a metal

d.

a base

Answer

d.

Explanation

The chemical properties of alkali (soluble bases) states that Alkali react with Ammonium Salts to produce Ammonia Gas when heated gently

Alkali + Ammonium Salt – > Salt + Ammonia Gas + Water [Heat gently]

Also a neutralisation reaction takes place when alkalis are heated with dilute acid

Dilute Acid + Alkali – > Salt + Water

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