Question

Which of the following correctly represents 360 g of water?
(i) 2 moles of $H_{2}O$
(ii) 20 moles of water
(iii) $6.022\times {10}^{23}$ molecules of water
(iv) $1.2044\times {10}^{25}$ molecules of water

• A. (i)
• B. (i) and (iv)
• C. (ii) and (iii)
• D. (ii) and (iv)

Answer 1

The correct option is D (ii) and (iv)

i) $2$ moles of water:
$1$ mole of water= molecular weight of water= $18$ g of water
$2$ moles of water = $18\times 2$=$36$ g of water.

ii) $20$ moles of water:
$1$ mole of water= mol.wt of water= $18$ g of water
$20$ moles of water=$18\times 20$=$360$ g of water

iii) $6.02\times {10}^{23}$ molecules of water= mol.wt of water=$18$ g of water

iv) $6.02\times {10}^{23}$ molecules of water= mol.wt of water=$18$ g of water
$1.2044\times {10}^{25}$ molecules of water= $\frac{1.2044\times {10}^{25}}{6.02\times {10}^{23}}$ moles of water = $20$ moles of water = $360$ g of water.
Therefore option $D$ (ii and iv) is correct.