Hello I am need to wyzant and I have been stuck for many many long hours please actually help

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

So the coefficients in the chemical equations are the ratios/proportions.

1) Use the coefficients to find out how many moles of H2O is created

4.3 moles of HNO3 consumed, which relates to the 8 coefficient in the equation

4.3 to 8 = x to 4

4.3/8 = x/4

17.2 = 8x

x= 2.15

x = 2.15 moles of H2O

Now use the molar mass to convert 2.15 moles of H20 into grams.

1 mole of H2O = 1 + 1 + 16 = 18g

so 2.15moles = 2.15 x 18

=38.7g H2O

Hope that helps!