Question

The total positive charge in a glass of water containing 180 gm of water is approximately :

• A. $1.0 \times 10^7$ coulomb
• B. $6.03 \times 10^7$ coulomb
• C. $1.80 \times 10^7$ coulomb
• D. $1.20 \times 10^7$ coulomb

Answer 1

Answer: (A)

$1.0 \times 10^7$ coulomb

Answer 2

The number of molecules in 18 g of water $= 6.02 \times 10^{23}$ $\therefore$ Number of molecules in 180 g of water $= 6.02 \times 10^{23} \times \frac{180}{18} = 6.02 \times 10^{24}$ The number of protons in a molecule of water = 10 So, total number of protons, $n = 6.02 \times 10^{24} \times 10 = 6.02 \times 10^{25}$ The total charge, q = ne $= 6.02 \times 10^{25} \times 1.6 \times 10^{-19} = 0.96 \times 10^7$ $\approx \, 1.0 \times 10^7 \, C$.