If 45.00 g of precipitate is formed from the reaction of 0.100 mol/L HCL(aq) and 0.124 mol/L AgNO3(aq) what volume in litres of AgNO3 did we
add?

Approximately (rounded to three significant figures) assuming that is in excess.

Explanation:

When and precipitate, (the said precipitate) and are produced:

(verify that this equation is indeed balanced.)

Look up the relative atomic mass of and on a modern periodic table:

Calculate the formula mass of the precipitate, :

.

Calculate the number of moles of formula units in of this compound:

.

Notice that in the balanced equation for this reaction, the coefficients of and are both one.

In other words, if (the other reactant) is in excess, it would take exactly of formula units to produce of formula units.

Hence, it would take of formula units to produce of formula units.

Calculate the volume of the solution given that the concentration of the solution is :

.

(The answer was rounded to three significant figures so as to match the number of significant figures in the concentration of .)

In other words, approximately of that solution would be required.