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

Question 11

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Question

MCQ▾

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 12

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Question

MCQ▾

The diagram shows reactions of substance Y. Find Y.

Identifying the substance Y

Identifying the Substance Y

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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 SaltsAmmonia Gas to produce 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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