Answer: Cu + 4HNO3 -> Cu(NO3)2 + 2NO2 + 2H2O
Explanation: The balanced chemical equation for the reaction of copper metal with nitric acid is as follows:
Cu + 4HNO3 -> Cu(NO3)2 + 2NO2 + 2H2O
Here's how you can break down the equation:
1. Start with the reactants: copper metal (Cu) and nitric acid (HNO3).
2. Identify the elements involved in the reaction: copper (Cu), hydrogen (H), nitrogen (N), and oxygen (O).
3. Count the number of atoms for each element on both sides of the equation to ensure the equation is balanced.
4. Begin by balancing the elements that appear in only one compound on each side of the equation. In this case, copper appears in only one compound on the left side, so we start by balancing it.
5. The coefficient "1" is automatically assumed for copper, so there is one copper atom on both sides.
6. Next, balance the hydrogen and oxygen atoms in nitric acid (HNO3). There are four hydrogen atoms and three oxygen atoms in HNO3. To balance the hydrogen, we need to add 4 in front of the HNO3 on the left side, resulting in 4HNO3.
7. Balancing the oxygen requires adding two water molecules (H2O) to the right side, resulting in 2H2O.
8. Now, let's balance the nitrogen atoms. There is one nitrogen atom in nitric acid, so we have one nitrogen atom on the left side.
9. Finally, balance the nitrogen dioxide (NO2) product. Since there are two nitrogen atoms in copper nitrate (Cu(NO3)2), we need to add 2 in front of NO2 on the right side, resulting in 2NO2.
10. Double-check the equation to ensure all elements are balanced. In this case, we have one copper atom, four hydrogen atoms, one nitrogen atom, and six oxygen atoms on both sides.
Thus, the balanced chemical equation for the reaction of copper metal with nitric acid is:
Cu + 4HNO3 -> Cu(NO3)2 + 2NO2 + 2H2O