Question

List the characteristics of cork. How are they formed? Mention their role.
a) Write the formula of

(i) Magnesium hydroxide
(ii) Hydrogen sulphide
(iii) Potassium chloride
(iv) Calcium oxide
(v) Barium chloride
(vi) Ammonium sulphate
b) Calculate the number $f$ moles (i) $64g$ of oxygen atom (ii) $24.066\times {10}^{23}$ number of oxygen atom. (at. mass of oxygen = $16u$ )

Answer 1

(a) Magnesium hydroxide= $Mg(OH{)}_2$

Hydrogen sulphide= $H_{2}S$

Potassium chloride= $KCl$

Calcium oxide= $CaO$

Barium chloride= $BaC{l}_2$

Ammonium sulphate= $N{H}_4(S{O}_4{)}_2$

(b)(i) Molar mass of $O_2$ is $16gm$

$\therefore 64gm$ of oxygen= $\frac{64}{16}=4$ mole of oxygen

(ii) Number of moles of $O_2=\frac{24.088\times {10}^{23}}{6.022\times {10}^{23}}=4$ moles