Question

Q1. A Cup contains 250 g of water. The number of negative charge present in Cup of water ?​

Answer 1

Given:

Mass of water,$=250g$

The Molecular mass of water $=18g$

Number of molecules in $=18g$ of water

$=6.02*10^{23}$

Solution:

Number of molecules in one cup of water

$=\frac{250}{18} *6.02*10^{23}$

Each molecule of water contains two hydrogen atoms and one oxygen atom,

i.e., $10$ electrons and $10$ protons.

Total negative charge present in one cup of water

$=\frac{250}{18} *6.02*10^{23} *10*1.6*10^{19} C$

Total negative charge present in one cup of water$=$$1.34*10^{7}$

Answer 2

Mass of water =250g

Molecular mass of water =18g

Each water molecule has two hydrogen atoms and one oxygen atom, totaling ten electrons and ten protons.

∴ One cup of water contains the total positive charge.

Because the density of water is 1 in cgs, 250 ml equals 250 gram. Water has two hydrogen atoms (2 protons) and one oxygen atom in each molecule (8 protons). So there will be 10 × 8.36 x 1024 = 8.36 x 1025 protons in 250 g of water. So one cup of water has a total positive and negative charge of 13.3 mega coulombs, resulting in a charge of zero.