A 3.81-gram sample of NaHCO3 was completely decomposed in an experiment.

2NaHCO3 → Na2CO3 + H2CO3

In this experiment, carbon dioxide and water vapors combine to form H2CO3. After decomposition, the Na2CO3 had a mass of 2.86 grams.

Determine the mass of the H2CO3 produced.

Calculate the percentage yield of H2CO3 for the reaction. Show your work or describe the calculation process in detail.
PLEASE HELP!

A) 1.67 grams H2CO3

Explanation:

A. This is a gram to gram conversion so first you need to find the atomic mass for 1 mole of Na2CO3 (105.988 grams) you'll then divide by how many grams you have (2.86) by 105.988 which will give you 0.02698419

0.02698419 is how many moles of Na2CO3 you have

Next you'll use the coefficients to find how many moles of H2CO3 you have and since both the coefficients are the same (1) you know you have 0.02698419 moles of H2CO3

You're then going to multiply this by the atomic mass of H2CO3 (62.024 grams) to get 1.6736674 grams of H2CO3

Now convert this number in sig figs

I'm so sorry but I don't know how to do B