Question

A titration was performed in a lab situation. H2SO4 was titrated with NaOH. The following data was collected:
mL of NaOH used = 43.2 mL
concentration NaOH = 0.15 M
mL H2SO4 = 20.5 mL
Notice that H2SO4 releases 2 H+ per mole.

What is the concentration of H2SO4?
a) 0.036 M
b) 0.16 M
c) 0.63 M
d) 6.3 M

Answer 1

1) you have to write down and balance the neutralization equation
2) calculate how many moles of NaOH you have in 43.2 mL 0.15 M.
moles= Molarity x Volume (L)
3) according to the soichiometry of the reaction calculate how many moles of H2SO4 you need
4) calculate the molarity of H2SO4 (Molarity = moles/ volume in L) moles is the value that you calculate in 3) and volume you have to convert the 20.5 mL to L

Answer 2

ok. thank you.

Answer 3

did you got the answer?

Answer 4

no. I got the answer wrong. I thought it was 0.63 M. but that was incorrect.

Answer 5

do u still need the answer?

Answer 6

I think U might have got the equation wrong !
So the balanced equation for the titration would be :\[2NaOH + H _{2}SO _{4} \rightarrow Na _{2}SO _{4} + 2H _{2}O\]

Answer 7

Now you find the no. of moles of NaOH as they have given us the volume and the concentrations ! Use \[C = \frac{ n }{ V }\]

Answer 8

remember no of moles of NaOH is twice the number of H2SO4 ( Look at the equation) What I go for this was \[0.15 * 43.2 * 10^{-3} = 6.48 * 10^{-3}\]
So now divide the no of moles of NaOH by 2 to find out the no. of moles of H2SO4
That would be 3.24 * 10 ^-3
Now again use C=n/v for H2SO4
and obtain the concentration .
Always remember to convert ml to liters.
So finally I obtained 0.158 which is approximately equals to 0.16 the 2nd answer !