Question

What will be the resulting normality of $NaCl$ solution formed on mixing $200ml$ of decimolar $NaOH$ with $40ml$ of semimolar $HCl$ ?

• A. $0.25N$
• B. $0.083N$
• C. $0.39N$
• D. $0.5N$

Answer 1

The correct option is B $0.083N$

The equation is,
$NaOH$ $+$ $HCl$ $\to$ $NaCl$ $+$ $H_{2}O$
Initially, $200\times 0.1$ $40\times 0.5$
$20$moles $20$ moles $0$ $0$
After
Some time $0$ $0$ $20$ $20$
Since both the acid and the base are present in equal amounts, complete neutralization takes place.
Now the total volume is $200+40=240ml$
Molarity of $NaCl$ formed = moles / volumes (in liters)
$=1000/12=83.33$
As the n-factor is $1$ in this case molarity is equal to normality.
Therefore, Resultant Normality $=83.33$