Chm stoichiometry

Question

How many milliters of a 0.200 M HNO3 solution are needed to dissolve 0.750 g of Cu

Answer 1

HNO3 (nitric acid) reacts with copper(s) as follows: Cu(s) + 4HNO₃----> Cu(NO₃)₂ + 2NO₂ + 2H₂O. We need to convert the mass to moles and then calculate the volume needed to produce that number of moles. 0.750 grams of copper X 1 mole/63.55 grams=0.0118 moles copper. We need 4 times this amount of moles of HNO₃ so 0.0472 moles HNO₃. Using the relationship (Molarity))(Volume)= moles, we find Volume (L)=0.0472 moles/0.200M=0.236 L =236 mL.