Name the sodium compound which is used for softening hard water.
$ Mg(OH)_2 $
$ Ca{(OH)} _{3} $
$Al_{2} O _{3} $
$Na _{2} CO _{3} \cdot 10 H _{2} O$
How is the concentration of hydronium ions $(H_3O^+)$ affected when a solution of an acid is diluted ?
Which gas is usually liberated when an acid reacts with a metal? Illustrate with an example. How will you test for the presence of this gas ?
You have two solutions, $A$ and $B$. The $pH$ of solution $A$ is $6$ and $pH$ of solution $B$ is $8$. Which solution has more hydrogen ion concentration Which of this is acidic and which one is basic?
Name the substance which on treatment with chlorine yields bleaching powder.
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 ?