WBJEE 2013 Chemistry Solved Paper

Now [H+] = 10−7 mole / litre
Now 1000 ml contains 10−7 mole H+
1ml '' ''

10−7

1000

mole H+
1.33 × 10−7 ml — ''1.33 × 10−17
10 million = 10−7
so, 10 million-th part of 1.33 cm3= 1.33 × 10−7 ml
So, no. of H+ ions = 1.33 × 10−17 × NA