Hola I need so much help with my chemistry homework please can someone actually help me as soon as possible please

Question

1.) 3 Cu + 8HNO3 → 3 Cu(NO3)2  + 2 NO + 4 H2O

In the above equation, how many grams of water can be made when 4.3 moles of HNO3 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.) S  + 6 HNO3 → H2SO4 + 6 NO2 + 2 H2O

In the above equation, how many grams of water can be made when 7.4 moles of HNO3 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

Sulfur       32

Oxygen   16

please please just solve and explain

Answer 1

Hello, Holly,

1.) how many grams of water can be made when 4.3 moles of HNO3 are consumed?

We know from the balanced equation that we'll get 4 moles of water for every 8 moles of nitric acid. The molar ratio is 0.5. It we start with 4.3 moles of nitric acid, we'll get 2.15 moles of water. Grams water = (2.15 moles)*(18 g/mole) = 38.7 g H₂O

2) In the above equation, how many grams of water can be made when 7.4 moles of HNO3 are consumed?

The molar ratio of H₂O to HNO₃ is 2/6, or 1/3. (7.4 moles)(1/3) = 2.43moles water,

(2.43 moles)*(18g/mole) = 43.7 grams H₂O

I hope this helps,

Bob