Question

100 ml of 0.2 M HCl reacts with sodium hydroxide solution is completely. THe mass of NaOH reacted is ??
1.2g
0.6g
2.2g
0.8g

Answer 1

Explanation :

Given,

100 ml of 0.2 M - HCL

and sodium hydroxide i.e. NaOH

Mole of HCl = Molarity × Volume in litre

= 0.2 × 100/1000

= 0.02 mole

0.02 mole of (OH - minus ) requires,

0.02 mole of (Na -positive) for complete neutralization.

Moles of NaoH = 0.8 / 40

( Here 40 is molar mass of NaOH )

= 1 / 50

= 0.02

we put direct options above ↑

we can find, NaoH → Na+ + OH -

mole of NaOH = W / Molar mass

0.02 = W / 40

W = 0.02 × 40

W = 0.8 g

so, Option no. D) 0.08 g is correct. The mass of NaOH is 0.08 g