Yield Question (1 Viewer)

[_ShiFTy_]

What is the maximum yield in grams of NO₂ that can be obtained if 10g of O₂ and 10g of N₂ are reacted?

2O₂ + N₂ --> 2NO₂

Thats pretty much all I can do from my limited chemistry knowledge

 

[brenton1987]

What is the maximum yield in grams of NO₂ that can be obtained if 10g of O₂ and 10g of N₂ are reacted?

2O₂ + N₂ --> 2NO₂

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Oxygen
mass - 10 g
molar mass - 31.9988 g^.mol^-1
moles - 0.3125 mol

Nitrogen
mass - 10 g
molar mass - 28.0134 g^.mol^-1
moles - 0.3570 mol

1 stoichiometric mole of oxygen = 0.15625 mol so,
1 stoichiometric mole of nitrogen = 0.1785
Oxygen is the limiting reagent so the number of moles of NO₂ must be the same as the number of moles of O₂.

Nitrogen Dioxide
moles - 0.3125 mol
molar mass - 46.0055 g^.mol^-1
mass - 14.3767 g

 

[_ShiFTy_]

Thanks for that brenton, i think i've got those types of questions down pat

However i'm not quite sure on some other ones like these:

1) CO(g) reacts with H₂ to form CO₂(g) and H₂(g) What is the percentage yield if 1.8g H₂(g) gas is formed starting with 50.0g of CO(g) and 40.0g of H₂?

Answer is 50%

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2) The number of grams of O₂ required to convert 1.0 gram of H₂ to H₂O is?

Answer is 8.0g

EDIT: I think i did Question 2 but i'm not sure...is the question basically asking you to find the minimum mass of oxygen needed for it to be a limiting reagent?

Hydrogen
mass - 1 g
molar mass - 2.0158 g.mol-1
moles - 0.4961 mol

1 stoichiometric mole of hydrogen = 0.2480

Oxygen
mass - ?
molar mass - 31.998 g.mol-1
moles - 0.2480 (using the value from above?)

Mass = 31.998 x 0.2480 = 7.935 ~ 8g

 

[brenton1987]

1) CO(g) reacts with H₂ to form CO₂(g) and H₂(g) What is the percentage yield if 1.8g H₂(g) gas is formed starting with 50.0g of CO(g) and 40.0g of H₂?

2) The number of grams of O₂ required to convert 1.0 gram of H₂ to H₂O is?

The reaction in question one is not possible with the reactants. CO + H₂ --> CO₂ + H₂
I think the reactant is supposed to be H₂O which would make the formula CO + H₂O --> CO₂ + H₂. Its the water shift reaction used for hydrogen production in ammonia synthesis.
Please check your notes for the correct reactants.

I got 7.9 g for question two. The limiting reagent is hydrogen (1 g), so the moles of hydrogen reacting is the same as the moles of oxygen that can react.
Remember the question gave the mass of hydrogen as 1.0 g so your answer should be to 1 d.p.

 

[_ShiFTy_]

Yep the first question is indeed CO + H₂O --> CO₂ + H<sub>2

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[brenton1987]

I got 50% for question one.