Question

How many grams of Na2CO3 can be produced from 2.715 g NaHCO3?

Answer 1

First, balance the equation:

Na2CO3 + 2HNO2 --> 2NaNO3 + CO2 + H2O

Second, convert 100g of NaNO3 to moles:

100g NaNO3 x 1mol/84.96grams
the grams cancel out, divide 100 by 84.96 to get moles.

Third, use the mole ratio from the equation to solve for Na2CO3 needed:

1.18 mol NaNO3 x 1 mol Na2CO3/2 mol NaNO3
The mole ratio is taken from the balanced equation. Now, cancel out the NaNO3 by dividing 1.18 by 2.

The moles of Na2CO3 needed: .59 moles, using two significant figures.

Answer 2

Rose, all of these stoichiometry problems are worked the same way.
Step 1. Write the balanced equation.
2NaHCO3 + heat ==> Na2CO3 + H2O + CO2

Step 2. Convert what you have (in this case g NaHCO3) to moles. moles = grams/molar mass

Step 3. Using the coefficients in the balanced equation, convert moles of what you have (in this case moles NaHCO3) to moles of what you want (in this case moles Na2CO3).
moles Na2CO3 = moles NaHCO3 x (2 moles NaHCO3/1 mole Na2CO3) = moles NaHCO3 x (2/1) = ??

Step 4. Now convert moles from step 3 to grams. g = moles x molar mass.

Memorize how to do these four steps You will use them an indeterminate number of times in chemistry.

Answer 3

Did I read the wrong problem? I don't see anything about HNO2.