JEE Main 12 Jan 2019 Morning Question 27

Question: 50 mL of 0.5 M oxalic acid is needed to neutralise 25 mL of sodium hydroxide solution. The amount of NaOH in 50 mL of the given sodium hydroxide solution is [JEE Main Online Paper Held On 12-Jan-2019 Morning]

Options:

A) 10 g

B) 80 g

C) 40 g

D) 20 g

E) None of these

Show Answer

Answer:

Correct Answer: E

Solution:

  • $ N _1V _1=N _2V _2 $ $ N _1 $ (oxalic acid) $ =2\times 0.5N $ $ 1\times 50=N _2\times 25\Rightarrow N _2=2N $

    Normality $ =\frac{wt.}{eq.wt.}\times \frac{1000}{V(mL)} $

    $ \Rightarrow $ $ 2=\frac{wt.}{40}\times \frac{1000}{50} $ weight = 4g