Answer to Question #197243 in General Chemistry for Muhammad wailu

Question

(A) containing 3.70gdm-3 of an acid H2X and (B) containing 2.15g NaOH per 250cm-3 of solution assume you carry out titration with the two solution and obtained the average titre value of 24.00cm-3

Calculate the concentration of the solution B in moldm-3

Calculate the concentration of the solution of A in moldm-3

Calculate the relative molecular mass of the acid H2X

Answer 1

N1V1 = N2V2 works fine if you have values for three of the four variables. You can then solve for the fourth variable. As you correctly observe here, that approach won’t work.

One way to find equivalents is by multiplying N × V if we have a solution of known normality and volume.

But if the reactant is not a solution of known normality and volume, we have to use other methods.

In this problem, the only thing we know about the quantity of our NaOH reactant is its mass. Can we convert that to equivalents? We can if we know the equivalent mass of NaOH. Since it reacts 1:1 with a monoprotic acid, equivalent mass = molar mass.