Hi, may I know why Lead (II) is the correct answer? Thank you!
Question
- An aqueous solution contains a cation which has the following properties.
- Forms a white precipitate with sodium carbonate solution
- Forms a white precipitate with sodium sulphate solution
Which of the following could be the cation?
A \mathrm{Cu}^{2+}
B \mathrm{Fe}^{3+}
C \mathrm{Pb}^{2+}
D \mathrm{Zn}^{2+}
Answer
Hi Jane,
For this question you can refer to the table below:
As for carbonate salts, all of them are insoluble except for:
\mathrm{Na_2CO_3, \space K_2CO_3, \space (NH_4)_2CO_3}
(Best to memorize this as it is important)
So based on the information above, \mathrm{Pb}^{2+} fits the description.
Hope this helps! 
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