Answer: The balanced chemical equation is written below.
Step-by-step explanation:
Double displacement reaction is defined as the reaction in which exchange of ions takes place.
![AB+CD\rightarrow AD+CB](https://img.qammunity.org/2021/formulas/chemistry/college/til2qmf2xcrzz6r78tiqz8h6wznpl64lxp.png)
The chemical equation for the reaction of hydrochloric acid and potassium sulfide follows:
![2HCl(aq.)+K_2S(aq.)\rightarrow 2KCl(aq.)+H_2S(g)](https://img.qammunity.org/2021/formulas/chemistry/middle-school/k8sptdyp63reffo3xdax9hx824k2w4kjbj.png)
By Stoichiometry of the reaction:
2 moles of hydrochloric acid reacts with 1 mole of potassium sulfide to produce 2 moles of potassium chloride and 1 mole of hydrogen sulfide gas
Hence, the balanced chemical equation is written above.