A solution of X2CO3 has a concentration of 15.2 g/dm^3. 25 cm^3 of this solution require 27.5 cm^3 of 0.2 M HCl for complete reaction. Calculate the ralative atomic mass of X

Answer 1

1 dm^3 = 1000 cm^3 = 1 liter
so

X2CO3 is 15.2 g/liter

a liter of this requires 27.5/25 or 1.1 liters of .2 M HCl
1.1 * .2 = .22 mols of HCL

X2CO3 + 2 HCl --> 2 XCl + H2CO3 maybe?

so we only need .11 mols of X2CO3
.11 mols of X2CO3 weigh 15.2 grams
1 mol X2CO3 weighs 138 grams
C is 12
O3 is 48
138 - 12 - 48 = 78
so X2 is 78 so x is 39
(Potassium? K2CO3 )