Please Help! In the reaction of nickel with concentrated nitric acid, the products are nickel (III) nitrate,?

Question

water and dinitrogen monoxide, sometimes called nitrous oxide. If 150 ml of nitrous oxide were collected over mercury at 42 degrees C and under a pressure of 74.5 cm of mercury, how many grams of nickel had reacted? please explain

Answer 1

The first thing to do is to balance the equation.

Ni + HNO3 ----> Ni(NO3)3 + N2O is what we are told.

There must be water given off as well:

Ni + HNO3 ----> Ni(NO3)3 + N2O + H2O

Ni goes up from ox st 0 to +3, and N comes down from +5 to +1. This gives us a ratio of 4:3 Ni:N (that is, the N that is reduced).

8Ni + 30HNO3 ----> 8Ni(NO3)3 + 3N2O + 15H2O

Now you can see that there is a 3:8 mole ratio between N2O and Ni. So calculate the moles of N2O, using the data, and then you're home and dry!