GIVEN THE FOLLOWING CHEMICAL EQUATION:

3 +Cu +8 HNO3 = 3 Cu(NO3)2 + 2 NO + 4 H2O.

1).HOW MANY MOLES OF Cu(NO3)2 ARE PRODUCED WHEN 3 MOLES OF Cu REACT?

2).HOW MANY MOLES OF Cu MUST REACT TO PRODUCE 4 MOLES OF NO?

3). If 4 moles of NO ARE PRODUCED HOW MANY MOLES OF h2o are also produced?

You let the coefficients in the balanced equation tell you the answer.

For #1.
mols Cu(NO3)2 = mols Cu x (3 mols Cu(NO3)2/3 mols Cu) = 3 x 3/3 = 3.

For #2.
mols Cu = mols NO x (3 mols Cu/4 mols NO) = 4 mols NO x 3/4 = 3 mols Cu.
Note how the factor used converts what we have to what we want (in the first example what we have is 3 mols Cu and what we want is mols Cu(NO3)3. In the second example, what we have is 4 mols NO and what we want is mols Cu.
The third one is done the same way. This is the same as the problem you posted earlier; however, this is the systematic way of doing it.
Check my work carefully.

To answer these questions, we need to use the stoichiometry of the chemical equation. Stoichiometry is a relationship between the quantities of reactants and products in a chemical reaction.

1) To determine the number of moles of Cu(NO3)2 produced when 3 moles of Cu react, we need to compare the coefficients of Cu and Cu(NO3)2 in the balanced equation.

From the balanced equation: 3Cu + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O

We can see that the coefficient of Cu(NO3)2 is also 3, indicating that for every 3 moles of Cu that react, 3 moles of Cu(NO3)2 are produced.

Therefore, 3 moles of Cu will produce 3 moles of Cu(NO3)2.

2) To determine the number of moles of Cu required to produce 4 moles of NO, we need to compare the coefficients of Cu and NO in the balanced equation.

From the balanced equation: 3Cu + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O

We can see that the coefficient of Cu is 3, and the coefficient of NO is 2. This means that the ratio of moles of Cu to moles of NO is 3:2.

Using this ratio, we can set up a proportion:
3 moles of Cu / 2 moles of NO = x moles of Cu / 4 moles of NO

Cross-multiplying and solving for x, we get:
2x = 3 * 4
2x = 12
x = 12 / 2
x = 6

So, 6 moles of Cu must react to produce 4 moles of NO.

3) To determine the number of moles of H2O produced when 4 moles of NO are produced, we need to compare the coefficients of NO and H2O in the balanced equation.

From the balanced equation: 3Cu + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O

We can see that the coefficient of NO is 2, and the coefficient of H2O is 4. This means that the ratio of moles of NO to moles of H2O is 2:4, which simplifies to 1:2.

Using this ratio, we can set up a proportion:
2 moles of NO / 4 moles of H2O = 4 moles of NO / x moles of H2O

Cross-multiplying and solving for x, we get:
2x = 2 * 4
2x = 8
x = 8 / 2
x = 4

So, 4 moles of H2O are produced when 4 moles of NO are produced.