# Chemistry

Sodium hydrogencarbonate, NaHCO3, can be converted into sodium carbonate, Na2CO3, by heating. This is a thermal decomposition reaction in which water vapour and carbon dioxide are also products of the reaction. A student started with 16.8g of sodium hydrogencarbonate and collected 9.20g of sodium carbonate. A) Write a balanced symbol equation for the thermal decomposition. B) Calculate the percentage yield the student obtained.
I think for question A the balanced equation is: 2NaHCO3 NA2CO3 + CO2 + H2O

Then for question B you do 9.2/16.8 then multiply the answer by 100 to get the peecentage yield

Posted from TSR Mobile
(edited 6 years ago)
Thank you x
Original post by Tarick
I think for question A the balanced equation is: 2NaHCO3 NA2CO3 + CO2 + H2O

Then for question B you do 9.2/16.8 then multiply the answer by 100 to get the peecentage yield

Posted from TSR Mobile

Thanks for the first one but I found out the answer is 86.8% for part b. I have no idea how though
Mass of 1 mol of NaHCO3 = 84g

Mass of 1 mol of Na2CO3 =106g

Mole ratio is 2:1.

Moles of NaHCO3 = (16.8÷84) =0.2.

mol (0.2÷2)= 0.1mol

To calculate the Theoretical yield of Na2CO3.
Moles x Mass of 1 mole Na2CO3 0.1 x 106 = 10.6g.

% yield = (Expected yield ÷ Theoretical yield) x 100.

(9.2÷10.6) x100 = 86.8% (1 d.p).

(Mr. Segun Aluko)
(edited 1 year ago)