J.R. S. answered 02/18/21
Ph.D. University Professor with 10+ years Tutoring Experience
Write the correctly balanced equation:
Na2CO3 + 2HCl ==> 2NaCl + CO2 + H2O
Note the mol ratio in the balanced equation of HCl to Na2CO3, i.e. it is 2 : 1
So, we find moles of Na2CO3, then times 2 to get moles of HCl needed, then convert to volume:
moles Na2CO3 present = 2.00 g x 1 mol/106 g = 0.00943 moles
moles HCl needed = 0.00943 mol x 2 mol HCl/mol Na2CO3 = 0.01886 moles HCl
To find the volume of HCl, we use the fact that it is 0.150 M which = 0.150 mol/L...
(0.150 mol/L)(x L) = 0.01886 moles
x = 0.126 L = 126 ml of HCl needed