Hi um I am in desperate need of assistance with my chemistry homework as soon as possible please please thank you

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

To answer this question, you need to remember that the units of molar mass are g/mol.

Question 1:

In the above equation, for every 2 moles of HNO3 that are consumed, 1 mole H2O is made. You can see this because every time you consume 8 mol HNO3 is consumed, you make 4 mols H2O. If you take the ratio between mols HNO3 and mols H2O, the answer is 2:1.

Step 1: So if 4.3 mols HNO3 are consumed, (4.3/2) mols H2O are made = 2.15

Step 2: Convert mols of H2O to grams of H2O

Solution: 2.15 mols of H2O x molar mass of H2O = 2.15 x (1+(16x2)) g/mol =141.9 grams of H2O

Question 2 is solved the same way except the ratio of HNO3:H2O is 3:1 instead of 2:1.