Question

Nickel metal reacted with oxygen: Ni (s) + O2 (g) --> Ni2O3 (s). 95.00g of Nickel is reacted with 2.000L oxygen at 10.56 atm and 30.00 degrees Celsius. At the end of the reaction the pressure was reduced to 7.56 atm at the same temperature and volume. How many grams of Nickel (III) oxide are produced?