Home / AS & A Level Chemistry 11.4 The reactions of chlorine Exam Style Practice Questions Paper 1
X, Y and Z are three aqueous solutions. Equal volumes of pairs of the solutions are mixed and observations noted.
X mixed with Y shows no reaction.
X mixed with Z shows an immediate reaction.
Z mixed with Y shows no reaction.
What are X, Y and Z?
| X | Y | Z | |
|---|---|---|---|
| A | \(\mathrm{Br_2(aq)}\) | \(\mathrm{I_2(aq)}\) | \(\mathrm{HBr(aq)}\) |
| B | \(\mathrm{Cl_2(aq)}\) | \(\mathrm{I_2(aq)}\) | \(\mathrm{HBr(aq)}\) |
| C | \(\mathrm{HCl(aq)}\) | \(\mathrm{HI(aq)}\) | \(\mathrm{Br_2(aq)}\) |
| D | \(\mathrm{HCl(aq)}\) | \(\mathrm{Br_2(aq)}\) | \(\mathrm{HBr(aq)}\) |
Correct Answer: \( \boxed{\mathrm{B}} \)
Chlorine is a stronger oxidising agent than bromine and iodine.
Therefore, the correct answer is (B).
An excess of chlorine gas is bubbled into hot potassium hydroxide solution.
Which chlorine-containing species are present in the final solution?
Correct Answer: \( \boxed{\mathrm{B}} \)
Chlorine reacts with hot, concentrated potassium hydroxide by disproportionation:
\(\mathrm{3Cl_2+6OH^-\rightarrow5Cl^-+ClO_3^-+3H_2O}\)
Therefore, the final solution contains chloride ions and chlorate(V) ions.
Hence, the correct answer is (B).
In an experiment, \(0.600\,\mathrm{mol}\) of chlorine gas, \(\mathrm{Cl_2}\), is reacted with an excess of hot aqueous sodium hydroxide. One of the products is \(\mathrm{NaClO_3}\).
Which mass of \(\mathrm{NaClO_3}\) is formed?
Correct Answer: \( \boxed{\mathrm{A}} \)
Hot concentrated sodium hydroxide reacts with chlorine according to:
\(\mathrm{3Cl_2+6NaOH\rightarrow5NaCl+NaClO_3+3H_2O}\)
From the equation:
\(3\,\mathrm{mol}\) of \(\mathrm{Cl_2}\) produce \(1\,\mathrm{mol}\) of \(\mathrm{NaClO_3}\).
Moles of \(\mathrm{NaClO_3}\):
\(\mathrm{\dfrac{0.600}{3}=0.200\,mol}\)
\(M_r(\mathrm{NaClO_3})=23.0+35.5+3(16.0)=106.5\)
Mass:
\(\mathrm{0.200\times106.5=21.3\,g}\)
Therefore, the correct answer is (A).