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Chemistry Past Questions and Answers

Neco Chemistry Questions

Question 146:

What volume of carbon (IV) oxide in dm ³ is produced at s.t.p. when 2.50g of CaCO₃ reacts with excess acid according to the following equation? CaCO₃(s) + 2HCI(aq) → CaCl₂(aq) + H₂O(1) + CO₂(g)

[CaCO₂ 100; molar volume of a gas at s.t.p. = 22.4dm ³]

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A 0.28
B 0.56
C 2.24
D 5.6
E 11.2

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Question 147:

The following equations represent redox reactions EXCEPT

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A Ba²⁺(aq) + SO^2-₄ (aq) → BaSO₄(s)
B Cl₂(g) + 2Br^- (aq) → 2CI ^- (aq) + Br₂(g)
C Fe²⁺(aq) + ½ C I₂(aq) → Fe³⁺ (aq) + CI^-(aq)
D 2Fe³⁺(aq) + Sn²⁺(aq) → 2Fe²⁺(aq) Sn⁴⁺ (aq)
E Zn(s) + CU²⁺(aq) → Zn²⁺(aq) + CU(s)

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Question 148:

A colourless gas with characteristics odour which dissolves in water to form an alkaline solution is ____________

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A Ammonia
B Carbon(IV)oxide
C Hydrogen chloride
D Sulphur (IV) oxide
E Sulphur (VI) oxide

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Question 149:

Which of the following equations is NOT balanced?

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A CH₄(g) + 20₂(9) → CO₂(g) + 2H₂O(g)
B CU(S) + HNO₃(aq) → Cu(NO₃)₂(aq) + 4H₂O(I) + NO(g)
C 2KCIO₃(s) → 2KCI(s)+ 3O₂(g)
D NaH(s) + H₂O(1) → NaOH(aq) +H₂(g)
E Na₂SO₄(aq) + BaCl₂(aq) → BaSO₄(s) + 2NaCl(aq)

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Question 150:

The process involved in the decomposition of sugar by an enzyme is called ____________

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A Dehydration
B Esterification
C Fermentation
D Polymerization
E Saponification

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