Neco Chemistry Past Questions and Answers

Question 11:

• NECO 2001

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

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. –

Question 12:

• NECO 2001

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

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).

Question 13:

• NECO 2001

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

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

Question 14:

• NECO 2001

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

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

Question 15:

• NECO 2001

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

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.