Please help me because I have needed help with my chemistry homework for many hours

Question

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

In the above equation, how many grams of water can be made when 13.5 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

please help by explaining and solving please

Answer 1

Hi Don R

First check to make sure you have a balanced reaction

Once that is confirmed you should be able to set up a ratio based on the moles in your balanced equation

For Example

Your Equation says that

8HNO₃, 8 moles of Nitric Acid makes 4H₂O or 4 moles of Water so

4 moles Water/8 moles Nitric Acid = x moles of Water/13.5 moles of Nitric Acid

You could cross multiply to solve for x moles of water

When you calculate x moles of water you can use the molar masses you have listed to convert your moles of water into grams of water

You can also do the same by converting everything into grams first according the moles in your balanced equation, and the moles given, then your answer would be in grams. You will need to use your masses given to calculate the molecular weights, of Nitric Acid and Water.

I hope this helps and by the way if your equation above is balance, it appears mathematically that the ratio of Nitric Acid to Water is 8 to 4 and 8/4 is 2 so the ratio of Nitric Acid to Water is 2 to 1.