$10 \,mL$ of a solution of $NaOH$ is found to be completely neutralised by $8 \,mL$ of a given solution of $HCl$. If we take $20 \,mL$ of the same solution of $NaOH$, the amount of $HCl$ solution (the same solution as before) required to neutralise it will be ...... $mL$

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 ?

Why does distilled water not conduct electricity, whereas rain water does ?

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.

How is the concentration of hydroxide ions $(OH^-)$ affected when excess base is dissolved in a solution of sodium hydroxide ?

Do basic solutions also have $H^+_{(aq)}$ ions ? If yes, then why are these basic ?