Question

0.7g of an unknown mixture of NaHCO3 and Na2CO3 is mixed with 3mL of 12M HCl.what is the mass of NaHCO3 and Na2CO3 in the mixture of NaHCO3 and Na2CO3? Use these equations:
NaHCO3+HCl--> NaCl+CO2+H2O
Na2CO3+2HCl-->2NaCl+CO2+H2O
mass of mixture= mass of NaHCO3+mass of Na2CO3
moles of NaCl=2(moles of Na2CO3)+1(moles of NaHCO3)

Answer 1

Let X = mass Na2CO3
then Y = mass NaHCO3
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X + Y = 0.7g
X(2/molar mass Na2CO3) + Y(1/molar molar mass NaHCO3) = 0.036

Solve the two equations simultaneously for X.