Metal compound $A$ reacts with dilute hydrochloric acid to produce effervescence. The gas evolved extinguishes a burning candle. Write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride.
$\underset{\begin{smallmatrix}
\text{Calcium} \\
\text{carbonate}
\end{smallmatrix}}{\mathop{CaC{{O}_{3(s)\,}}}}\,+\,\underset{Hydrochloricacid}{\mathop{2HCl}}\,\,\to $$\underset{Calcium\text{ }chloride\text{ }}{\mathop{CaC{{l}_{2(aq)}}}}\,\,+\,\underset{Carbon\text{ }dioxide}{\mathop{C{{O}_{2(g)}}}}\,$$\mathop { + {H_2}{O_{(l)}}}\limits_{water} $
Fresh milk has a $pH$ of $6$. How do you think the $pH$ will change as it turns into curd ? Explain your answer.
Name the substance which on treatment with chlorine yields bleaching powder.
How is the concentration of hydronium ions $(H_3O^+)$ affected when a solution of an acid is diluted ?
Why do $HCl$, $HNO_3$, etc., show acidic characters in aqueous solutions while solutions of compounds like alcohol and glucose do not show acidic character ?
$10 \,mL$ 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 ...... $mL$