Question

Stoich Problem Set

1. Calculate the number of grams of ammonia gas needed to react completely with 75.0 g copper(Il) nitrate. The unbalanced equation for the reaction is:       

NH3(g)+H2O(l)+Cu(NO3)2(aq)=NH4NO3(aq)+Cu(OH)2(aq)

2. When aluminum is heated in oxygen. aluminum oxide is formed.

a.Write a balanced equation to show this reaction.       

Answer 1

Cu(NO₃)₂ + 2NH₃ + 2H₂O → Cu(OH)₂ + 2NH₄NO₃

Moles of Cu(NO₃)₂$=\frac{75.0}{187.56}​=0.40mol$

Moles of 2NH₃ $=2×0.40= 0.80 mol$

Grams of Ammonia = $17.031×0.8=13.62 grams$

Aluminum reacts with oxygen to produce aluminum oxide as follows:

$4Al + 3O_2 → 2Al_2O_3$