State how the relative strength of van der Waals’ forces changes down Group 17.
State the physical state of each halogen at room conditions: chlorine, bromine and iodine.
Aqueous bromide ions, $\text{Br}^-(aq)$, are added separately to samples of $\text{Cl}_2(aq)$ and $\text{I}_2(aq)$. Describe what is observed in each case and explain your answer in terms of their relative reactivity as oxidising agents. Observation when added to $\text{Cl}_2(aq)$. Observation when added to $\text{I}_2(aq)$. Explanation.
Bleach is formed when $\text{Cl}_2$ reacts with cold $\text{NaOH}(aq)$. Write an equation for the reaction between $\text{Cl}_2$ and cold $\text{NaOH}$.
When $\text{ClO}^-(aq)$ is added to water, it acts as a Brønsted-Lowry base. Define the term Brønsted-Lowry base.
Write an ionic equation for the reaction of $\text{ClO}^-$ with $\text{H}_2\text{O}$.
The concentration of $\text{NaClO}$ in bleach S is $x\,\text{g dm}^{-3}$. $\text{NaClO}$ reacts with $\text{H}_2\text{O}_2(aq)$ as shown: $\text{H}_2\text{O}_2(aq) + $\text{NaClO}(aq) \rightarrow \text{H}_2\text{O}(l) + \text{NaCl}(aq) + \text{O}_2(g)$. A $5.00\,\text{cm}^3$ sample of S completely reacts with $\text{H}_2\text{O}_2(aq)$. The volume of $\text{O}_2(g)$ produced is $24.0\,\text{cm}^3$ under room conditions. Assume that only the $\text{NaClO}$ in S reacts with $\text{H}_2\text{O}_2(aq)$. Calculate $x$. Show your working.
Sodium chlorate(I), $\text{NaClO}$, oxidises dilute hydrochloric acid to produce three products. In the products that contain chlorine, the chlorine species have oxidation number $-1$ or $0$. During the reaction, no other species changes oxidation number. Use this information to complete the ionic equation: $\ldots\text{ClO}^- + \ldots\text{HCl} \rightarrow \ldots + \ldots + \ldots$.