Chemistry Mole to Mole Stoichiometric Conversions

Question

How many moles of NO are produced by the reaction of 6.35 grams of Cu with excess HNO_3, Given the equation below:

 

3 Cu_(S) + 8 HNO_{3 (aq)}= 3 Cu(NO₃)_{2 (aq)} + 2 NO_(g) + 4 H₂O_(l) 

Answer 1

In this problem you are given mass of copper and a balanced equation. You are asked to solve for the moles of NO.

1) convert 6.35 grams to moles by dividing by the molar mass of Cu. 6.35÷ 63.546= 0.099928 moles of Cu

2) Use the moles of copper and the balanced equation to solve for the moles of NO produced:

moles of copper x coefficient in front of NO, then ÷ by the coefficient in front of the Cu

(0.099928x 2) ÷ 3= 0.0222 moles of NO