STOICHIOMETRY: QUANTITATIVE INFORMATION ABOUT CHEMICAL REACTIONS

Question

What volume of 0.124 M NaOH , in milliliters, contains 30.0 g of NaOH ?

Volume= ___ mL

Answer 1

We know the concentration of the solution is 0.124 M of NaOH, so this tells us that there are 0.124 moles of NaOH in 1.0 liters of of solution. We want to know the volume of solution contains a certain amount of the solute (in this case 30.0 g of NaOH). Let's start by finding out how many moles of NaOH are in 30.0 g:

Molar mass of NaOH = 39.99 g/mol

30.0 g × (1 mol / 39.99 g) = 0.750 mol NaOH ------ notice I put grams in the denominator to cancel out grams and be left with moles.

Now we can set up a proportion:

0.124 mol 0.750 mol

¯¯¯1 L¯¯¯ = ¯¯¯x¯¯¯

Solve for x, and you get 6.05 L. Convert this into mL by multiplying by 1000, and your answer is 6050 mL.