58.8k views
5 votes
2Na2O2 + 2CO2 → 2Na2CO3 + O2

The percent yield of Na2CO3 when 7.80 g of Na2O2 is reacted with excess CO2 is 81.0 %.
What is the actual yield of Na2CO3?

If you know understand how this process works, please let me know how to do it, and the answer.
Thank you.

User Andez
by
6.2k points

2 Answers

3 votes

Answer:

8.58 g.

Step-by-step explanation:

  • To get the actual yield of a reaction, we can use the relation:

The percent yield = [actual yield]/[theoretical yield] x 100.

The percent yield = 81.0 %.

  • We need to calculate the theoretical yield:
  • From the balanced reaction: 2Na₂O₂ + 2CO₂ → 2Na₂CO₃ + O₂.
  • It is clear that 2.0 moles of Na₂O₂ react with 2.0 moles of CO₂ to produce 2.0 moles of Na₂CO₃ and 1.0 mole of O₂.
  • The no. of moles of reacted 7.80 g of Na₂O₂ = mass/molar mass = (7.80 g)/(77.98 g/mol) = 0.1 mol.
  • We can get the no. of moles of produced Na₂CO₃ using cross multiplication:

∵ 2.0 moles of Na₂O₂ produce → 2.0 moles Na₂CO₃.

∴ 0.1 mol of Na₂O₂ produce → 0.1 mol Na₂CO₃.

  • We can get the mass of 0.1 mol Na₂CO₃:

mass of 0.1 mol Na₂CO₃ = n x molar mass = (0.1 mol)(105.98 g/mol) = 10.598 g.

∵ The percent yield = [actual yield]/[theoretical yield] x 100.

∴ 81.0 % = [actual yield]/[10.598 g] x 100.

∴ [actual yield] = (81.0 %)(10.598)/(100) = 8.58 g.

User Letisia
by
6.4k points
3 votes

the actual yield is the amount of Na₂CO₃ formed after carrying out the experiment

theoretical yield is the amount of Na₂CO₃ that is expected to be formed from the calculations

we need to first find the theoretical yield

2Na₂O₂ + 2CO₂ ---> 2Na₂CO₃ + O₂

molar ratio of Na₂O₂ to Na₂CO₃ is 2:2

number of Na₂O₂ moles reacted is equal to the number of Na₂CO₃ moles formed

number of Na₂O₂ moles reacted is - 7.80 g / 78 g/mol = 0.10 mol

therefore number of Na₂CO₃ moles formed is - 0.10 mol

mass of Na₂CO₃ expected to be formed is - 0.10 mol x 106 g/mol = 10.6 g

therefore theoretical yield is 10.6 g

percent yield = actual yield / theoretical yield x 100%

81.0 % = actual yield / 10.6 g x 100 %

actual yield = 10.6 x 0.81

actual yield = 8.59 g

therefore actual yield is 8.59 g

User Deha
by
6.5k points