Round up the following up to three significant figures:

$0.04597$.

Round up the following up to three significant figures:

$2808$.

Calculate the molarity of a solution of ethanol in water in which the mole fraction of ethanol is $0.040$ (Assume the density of water to be one). Use the data given in the following table to calculate the molar mass of naturally occurring argon isotopes:
Isotope               Isotopic molar mass                    Abundance

${}^{36}\mathrm{Ar}$                  $35.96755 \mathrm{g} {\mathrm{mol}}^{-1}$                 $0.337\%$

${}^{38}\mathrm{Ar}$                  $37.96272 \mathrm{g} {\mathrm{mol}}^{-1}$                 $0.063\%$

${}^{40}\mathrm{Ar}$                  $39.9624 \mathrm{g} {\mathrm{mol}}^{-1}$                  $99.600\%$.

Chlorine is prepared in the laboratory by treating manganese dioxide (${\mathrm{MnO}}_2$) with aqueous hydrochloric acid according to the reaction.

$4 {\mathrm{HCl}}_{\left(\mathrm{aq}\right)} + {\mathrm{MnO}}_{2\left(\mathrm{s}\right)}\to 2{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)} + {\mathrm{MnCl}}_{2\left(\mathrm{aq}\right)} + {\mathrm{Cl}}_2 \left(\mathrm{g}\right)$

How many grams of $\mathrm{HCl}$ react with $5.0 \mathrm{g}$ of manganese dioxide?

Calculate the volume of $0.1\mathrm{N} {\mathrm{H}}_2{\mathrm{SO}}_4$ required to neutralize $200\mathrm{ml}$ of $0.2\mathrm{N} \mathrm{NaOH}$ solution.

It is an acid base neutralisation reaction.Hence, at the neutralisation point.

Number of equivalents of acid $=$ Number of equivalents of base.