Chemistry Past Questions and Answers

What is the oxidation number of Zinc in K<sub style='font-size: smaller;'>3</sub>ZCl<sub style='font-size: smaller;'>6</sub>?

Elements in the same period in the periodic table have the same ____________

Calculate the percentage by mass of nitrogen in calcium trioxonitratre (v)<br/>\((\mathrm{Ca}=40, \mathrm{~N}=14, \mathrm{O}=16)\)

Which of the following salts is slightly soluble in water?

Permanent hardness of water can be removed by ____________