JAMB Chemistry Past Questions & Answers - Page 311

1,551.

Which of the following reactions is correct as as written?

FeCl₂ + 3NH₄OH → Fe(OH)₃ + 3NH₄Cl

Pb₂O₃ + 4HCl → PbCl₂ + 2H₂O

PbNO₃ + H₂S → PbS + 2HNO₃

NaOH + H₂SO₄ → NaHSO₄ +H₂O

2NH₄NO₃ → N₂ + 2H₂O

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Correct answer is D

No explanation has been provided for this answer.

1,552.

If 1 litre of 2.2M sulphuric acid is poured into a bucket containing 10 litre of water,and resulting solution mixed thoroughly, the resulting sulpuric acid concentration will be?

2.2 M

1.1 M

0.22 M

0.11 M

0.20 M

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Correct answer is C

No explanation has been provided for this answer.

1,553.

On heating, under suitable conditions, 1 litres of monoatomic gas,X, combines with 1¹/₂ litres of an oxide, What is the formula of the oxide.

XO₃

X₂O₃

X₃O₂

XO₂

None of the above

View answer & explanation

Correct answer is B

No explanation has been provided for this answer.

1,554.

A sample of an oxide of mercury weighed 1.00g. When this was heated, oxygen was given off, and 1.00g of mercury metal only was left. What is the formula of the oxide?

Hg₂O

HgO₂

HgO

None of the above

View answer & explanation

Correct answer is E

Various oxides of mercury: Mercury(I) oxide (mercurous oxide), Hg\(_2\)O. Mercury(II) oxide (mercuric oxide), HgO.

No specific oxide of mercury is refered in the question.

1,555.

10cm3 of CO is mixed and sparked with 100cm3 of air containing 21% O2. If all the volumes measured at S.T.P. the volume of resulting gases would be?

90cm³

100cm³

105cm³

110cm³

115cm³

View answer & explanation

Correct answer is C

2CO(g) + O2(g) ---> 2CO\(_2\)(g)
2vol 1vol 2vol
Volume in cm\(^3\) Before sparking: 10 // 21
Volume in cm\(^3\) On sparking 10 // 5 // 10
Volume in cm\(^3\) After sparking: 0// 16 // 10
Total volume of resulting gas = Volume of [excess oxygen + CO\(_2\) produced + unreactive components]
= 16 + 10 + 79 → 105cm\(^3\)