Question

The total number of electrons present in 18 mL of water(density of water is 1 g $m{L}^{-1}$) is

• A. $6.02\times {10}^{22}$
• B. $6.02\times {10}^{23}$
• C. $6.02\times {10}^{24}$
• D. $6.02\times {10}^{25}$

Answer 1

The correct option is C $6.02\times {10}^{24}$

Density of water = $1g/cc$

Density =Mass/Volume

$1g/ml=M/18ml$

So, $M=18g$

Moles of water = mass/molar mass = 18/18 = 1

1 mole of water contains $=N_A$ molecules

The total electrons in water $=$ 2($H$) + 8($O$) $=10$

1 molecule of water contains = 10 electrons

1 mole water contains $=10\times N_A$ electrons

$N_A=$ Avogadro’s number

Hence, correct option is $C$.