4NH3 + 5O2 ==> 4NO + 6H2O Balanced equation
ALWAYS WORK IN MOLES, NOT IN GRAMS
moles of NO produced = 70.5 g NO x 1 mole/30 g = 2.35 moles NO
Since this represents only a 29.8% yield, find what 100% yield would be:
2.35 moles/0.298 = 7.89 moles of NO
From the balanced equation 4 moles NH3 produces 4 moles of NO. Calculate moles of NH3 needed:
7.89 moles NO x 4 moles NH3/4 moles NO = 7.89 moles NH3 needed
Find grams of NH3 needed:
7.89 moles NH3 x 17 g/mole = 134 g NH3 needed
Molar mass is the ratio of the mass to that amount of the substance. The mass of the barium nitrate in the formula unit is 23.0 grams.
<h3>What is mass?</h3>
The mass of a substance is the product of the molar mass of the compound and the number of moles of the compound.
Given,
Molar mass of barium nitrate = 261.35 g/mol
If,
have a mass of 261.35 g/mol then,
formula units will have a mass of,

Therefore, option C. 23.0 gm is the mass of barium nitrate.
Learn more about mass here:
brainly.com/question/24958554