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Chemistry Past Questions and Answers

Neco Chemistry Questions

Question 11:

NaCl(s) does NOT conduct electricity, but N(aq) does. This is because

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A NaCl(s) is non-ionic but NaCl(aq) is ion
B NaCl(aq) contains mobile electrons, where absent in NaCl(s).
C NaCl(aq) contains mobile ions which Nacl,) does not contain.
D NaCl(s) ionizes partiality while NaCl(aq) iodizes completely.
E NaCl(s) decomposes when heated but NCl(aq) is stable to heat. –

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Question 12:

To test for the presence of chloride ions in ion, correct sequence of reagents to use is ____________

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A Ba(NO₃)₂(aq) then HNO₃(aq).
B HCl(aq) then Ba(NO₃)₂(aq).
C HCl(aq) then Ag₃(aq).
D HNO₃(aq) then fresh FeSO₄(aq).
E HNO₃(aq) then AgNO₃(aq).

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Question 13:

Ethanol is a product of fermentation of simple sugars. Which method is used to separate ethanol from the other products?

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A Boiling off the ethanoic
B Filtration
C Fractional crystallisation
D Fractional distillation
E Isomerisation

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Question 14:

Which method is NOT used to determine rate of a reaction?

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A Change in amount of precipitate formed
B Change in equilibrium constant
C Change in intensity of colour
D Change in pH values.
E Change in total gas pressure

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Question 15:

Detergents are better than soaps for washing in hard water because ____________

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A Hard water contains insoluble calcium salts.
B They contain bleaching powder.
C They contain palmitic acid.
D They do not form insoluble calcium and magnesium salts.
E They are organic compounds.

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