25 cm^3 of 2mol/dm^3 Sodium hydrixude solution and 25cm^3 of 2 mol/dm^3 Sulphuric acid were mixed well to make a solution X. Calculate the concentration of Sulphuric acid in the final solution..

Question

anonymous · Answer

@Callisto @TuringTest

callisto · Answer

Sodium hydroxide?

anonymous · Answer

h2so4?

callisto · Answer

Do you mean sodium hydroxide for ''Sodium hydrixude''?

anonymous · Answer

yh

callisto · Answer

Can you write the chemical equation for the reaction first?

anonymous · Answer

2NaOH + H2SO4 ---> Na2SO4 + 2H20

callisto · Answer

In this reaction, what is the limiting agent?

anonymous · Answer

limiting agent means? i found the answer it is 1 moldm^-3 cn u check it

callisto · Answer

Hmm, I didn't get the same answer as you.

anonymous · Answer

can u shw ur working

callisto · Answer

Perhaps I didn't do it correctly, since I haven't studied chemistry for quite a long time..
No. of mole of H2SO4 used = 1/2 (no. of mole of NaOH) = (1/2) (2x25/1000) = x
*NaOH is the limiting agent that will be used up in the reaction.

No. of mole of H2SO4 left = no. of mole of H2SO4 - no. of mole of H2SO4 used
                                          = (2x25/1000) - x
                                          = y

Concentration of H2SO4 in the final solution = no. of mole of H2SO4 left / volume of the solution.
And I take volume of the solution remains unchange, that is 25cm^3 + 25cm^3 = 50cm^3

Did I do anything wrong?

anonymous · Answer

This is how i did, check if im wrong
2NaOH + H2SO4 ---> Na2So4  +2 H20

the molar ratio is tht, 2 moles of NAOH reacts with 1 mole of H2so4
when u calculate the number of moles in each reactnt it is 0.05 mole, which means 0.05 mol of Naoh react with 0.025 mol of H2so4...so there is 0.025 mole of H2so4 left

n = c*v/ 1000
0.025 = c * 25/1000
c = 1 mol dm^-3

callisto · Answer

Why is it 25cm^3 for your volume?

anonymous · Answer

should it be 50 or 25?

anonymous · Answer

im not sure of this

callisto · Answer

Hmm.. final solution, it's not just the volume of H2SO4, so I prefer using the total volume. But I'm not sure though. As I've said, I haven't studied chemistry for quite a long time!

anonymous · Answer

then the answer becomes 0.5 moldm^-3

callisto · Answer

That's what I got. Sorry for the late reply

anonymous · Answer

so my method is right?

callisto · Answer

The method is right, just the volume is not right/

anonymous · Answer

thanks alot :)

callisto · Answer

Welcome :)