Keerti added dilute Hydrochloric acid to four metals and recorded her observations as shown in the table given below:

Select the correct observation(s) and give chemical equation(s) of the reaction involved.

Aluminium sulphate and copper sulphate solutions were taken in two test tubes I and II respectively. Iron filings were then addd to both the solutions. The four students A,B, C and D recorded their observations in the form of a table as given on the next page. The correct set of observations have been recorded by the student:

A metal is treated with dilute sulphuric acid. The gas evolved is collected by the method shown in the figure: If the metal used above is zinc, choose the correct balanced chemical equation for the evolution of gas?

Potassium iodide solution is added to lead nitrate solution in a test tube. Select the correct observation from the table below:

What happens when piece of (a) zinc metal is added to copper sulphate solution ? (b) aluminium metal is added to dilute hydrochloric acid ? (c) silver metal is added to copper sulphate solution ? Also write the balanced chemical equation if the reaction occurs.

Varun took a sample A and added dilute hydrochloric acid to it. A colourless, odourless gas X was evolved which turned lime water milky. Identify sample A and the gas X evolved. Write a chemical equation to explain the reaction between Sample A and Hydrochloric acid. Why does the gas X turn lime water milky?