You have been provided with three test tubes. One of them contains distilled water and the other two contaln an acidic solution and a basic solution, respectlvely. If you are glven only red litmus paper. how will you identify the contents of each test tube ?

Plaster of Paris should be stored in a moisture-proof container. Explain why ?

Equal lengths of magnesium ribbons are taken in test tubes $A$ and $B$. Hydrochloric acid $(HCl)$ is added to test tube $A$, while acetic acid $(CH_3COOH)$ is added to test tube $B$. Amount and concentration taken for both the acids are same. In which test tube will the fizzing occur more vigorously and why ?

Fresh milk has a $pH$ of $6$. How do you think the $pH$ will change as it turns into curd ? Explain your answer.

Write word equations and then balanced equations for the reaction taking place when -

$(a)$ dilute sulphuric acid reacts with zinc granules.

$(b)$ dilute hydrochloric acid reacts with magnesium ribbon.

Give two important uses of washing soda and baking soda.