Question 1
Which of the following is a correct statement about the test for Fe2+ ions in solution?
add NaOH(aq); brown precipitate formed, soluble in NH3(aq)
add NaOH(aq); brown precipitate formed, insoluble in NH3(aq)
add NaOH(aq); green precipitate formed, soluble in NH3(aq)
add NaOH(aq); green precipitate formed, insoluble in NH3(aq)
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Question 2
Aqueous Cr3+ ions are reacted with an excess of aqueous sodium hydroxide.
Which product is formed?
Cr(OH)63-
Cr(OH)3
[Cr(OH)4(H2O)2]-
[Cr(OH)4]3-
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Question 3
What is observed when concentrated hydrochloric acid is added to an aqueous solution of CuSO4 until no further change occurs?
a colourless gas is evolved and a precipitate forms
a colourless gas is evolved and no precipitate forms
a precipitate forms that dissolves in an excess of concentrated hydrochloric acid
the solution changes colour and no precipitate forms
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Question 4
Which observation would confirm that ammonia gas is released when solid ammonium chloride is warmed with solid calcium hydroxide?
damp blue litmus paper turns red when touched onto the solid mixture
damp red litmus paper turns blue when touched onto the solid mixture
damp blue litmus paper turns red when held just above the solid mixture
damp red litmus paper turns blue when held just above the solid mixture
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Question 5
Compound T is a white crystalline solid.
When a sample of T was mixed with aqueous sodium hydroxide and heated, a pungent smelling gas was produced which turned damp red litmus paper blue. This same gas produced dense white smoke with hydrogen chloride gas.
Further testing of a solution of T with barium chloride solution produced a dense white precipitate which did not dissolve when dilute hydrochloric acid was added to the mixture.
What is the identity of compound T?
ammonium carbonate
ammonium sulfate
sodium carbonate
sodium sulfate
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