a solution of NaOH is prepared by dissolving 4 g of NaOH in 1 l of water.calculate the volume of HCl gas at STP that will neutralise 50 ml of this solution

Question

anonymous · Answer

how to solve the ques:     calculate the number of moles of the 50mL of solution of NaOH. 
                                     no. of moles of NaOH = no. of moles of OH-.
                                      as the question says complete neutralization, the number of
                                     moles of OH- must be equal to the number of moles of H+.
                                    and number of moles of H+ = no. of moles of HCl.

you are on the verge of solving the question once you reach this point.
we know, from the definition of 1mole, that 1mole= 22.4L of volume of gas.
so, x moles of HCl will occupy what volume??

simple unitary method.... 
multiply the no. of moles of HCl you get by 22.4L
the ans is the volume of HCl gas to completely neutralize the 50mL of NaOH solution. 
ans., is in Litres only.

i hope this helps...

anonymous · Answer

you can now solve the question by yourself.

samigupta8 · Answer

i din't get how can u calculate the moles of 50 ml solution of naoh

samigupta8 · Answer

f99 i got it now....

samigupta8 · Answer

25 ml of 2 N HCl,50 ml of 4N HNO3 and X ml of 5M H2S04 are mixed and total volume is made up to 1 l.50 ml of the resultant solution exactly neutralises 25 ml of 1 N Na2CO3 solution.the value of X is

anonymous · Answer

ok.. see,

$$Molarity = \frac{ mass of NaOH taken }{ Molar mass of NaOH }*\frac{ 1 }{ volume of solution (litres) }$$
ok with this?

you can calculate the molarity by 
putting mass of NaOH = 4g
and molar mass = 40g
and volume of solution = 1 litres.

molarity will come out to be 0.1M.

anonymous · Answer

ok good!