Posted by Deanna on .
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)

Chemistry 
DrBob222,
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.