Hello. It may not seem like it but I am under pressure and need so much help with my chemistry as soon as possible please please please ok please please please please

Question

1.) 2 NH3 + 3 CuO --> 3 Cu + N2 + 3 H2O

In the above equation how many moles of N2 can be made when 165.7 grams of CuO are consumed?

Round your answer to the nearest tenth. If you answer is a whole number like 4, report the answer as 4.0

Use the following molar masses. If you do not use these masses, the computer will mark your answer incorrect.:

Element	Molar Mass
Hydrogen	1
Nitrogen	14
Copper	63.5
Oxygen	16

2.) For the reaction C + 2H2 → CH4, how many moles of hydrogen are needed to make 123.3 grams of methane, CH4 ?

Round your answer to the nearest tenth. If you answer is a whole number like 4, report the answer as 4.0

Use the following molar masses. If you do not use these masses, the computer will mark your answer incorrect.:

Element	Molar Mass
Hydrogen	1
Carbon	12

Answer 1

(1) molecular mass of CuO = 63.5 + 16 = 79.5

165.7 g of CuO = 165.7 / 79.5 moles

3 moles of CuO produces 1 mole of N2 from the equation

1 mole CuO produces 1/3 moles of N2

(165.7 / 79.5) moles produces (1/3)x (165.7 /79.5) moles of N2

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(2)

Molar mass of CH4 = 12 + 4 x 1 = 16

123.3 g of CH4 = (123.3 / 16) MOLES

For each mole of CH4 you need 2 moles of H2

So you need 2 x (123.3 /16) moles of H2

Answer 2

Hello, Pam,

1.) 2 NH3 + 3 CuO --> 3 Cu + N2 + 3 H2O

In the above equation how many moles of N2 can be made when 165.7 grams of CuO are consumed?

The equation is balanced, and it tells us we'll get 1 mole of nitrogen, N₂, for every 3 moles of CuO, a molar ratio of 1/3. Let's find the moles of CuO by dividing its mass by it's molar mass: 165.7 grams/79.55grams/mole = 4.96 moles CuO. 1/3 that is 1.65 moles of N₂. 1.7 moles for 2 sig figs.

2.) For the reaction C + 2H2 → CH4, how many moles of hydrogen are needed to make 123.3 grams of methane, CH4 ?

This balanced equation promises 1 mole of CH₄ for every 2 moles of H₂. Find trhe moles of methane by dividing the mass by its molar mass: 123.3 g/79.6g/mole = 1.55 moles. Multiply by 2 to find how many moles of hydrogen are required. That is 3.1 moles to 2 sig figs.

Bob

[Please use the atomic weights posted in the table. I used atomic masses obtained from a table. The answers should be equivalent, but the rounded weights may be off slightly from those used in the supplied table.]