- Identify the product \(\text{Cu}(\text{NO}_3)_2\) as the only species containing the \(\text{NO}_3\) group.
- Note the coefficient of \(\text{Cu}(\text{NO}_3)_2\) is 3 and the number of nitrate groups per formula unit is 2.
- Calculate the total units by multiplying the coefficient by the number of groups per unit: \(3 \times 2 = 6\).
- Final answer is \(\boxed{6}\).
Explanation
- Analyzing the Chemical Equation
The provided chemical equation is:
\[3 \text{Cu} + 8 \text{HNO}_3 \rightarrow 3 \text{Cu}(\text{NO}_3)_2 + 2 \text{NO} + 4 \text{H}_2\text{O}\]
Our objective is to determine the total number of \(\text{NO}_3\) (nitrate) units on the products side of this balanced equation. The products are \(3 \text{Cu}(\text{NO}_3)_2\), \(2 \text{NO}\), and \(4 \text{H}_2\text{O}\). We need to examine these components to identify where \(\text{NO}_3\) groups are present.
- Identifying Nitrate Groups in Products
Examining the products, we find:
- \(3 \text{Cu}(\text{NO}_3)_2\): This compound contains the \(\text{NO}_3\) group. The formula \(\text{Cu}(\text{NO}_3)_2\) indicates that there are two \(\text{NO}_3\) groups for every one formula unit of copper(II) nitrate.
- \(2 \text{NO}\): This molecule contains one nitrogen atom and one oxygen atom, which is not equivalent to the \(\text{NO}_3\) nitrate group.
- \(4 \text{H}_2\text{O}\): This is water and contains no nitrogen or nitrate.
Thus, only the copper(II) nitrate compound contributes \(\text{NO}_3\) units.
- Calculating the Total Nitrate Units
The coefficient of \(\text{Cu}(\text{NO}_3)_2\) in the balanced equation is \(3\). Since each formula unit of \(\text{Cu}(\text{NO}_3)_2\) contains \(2\) nitrate (\(\text{NO}_3\)) groups, the total number of \(\text{NO}_3\) units is calculated by multiplying the coefficient by the number of groups per unit:
\[3 \times 2 = 6\]
Therefore, there are \(6\) units of \(\text{NO}_3\) on the products side.
Examples
In chemical engineering, calculating the amount of specific functional groups like nitrates is essential when designing synthesis processes or managing chemical waste. For example, knowing the number of nitrate units formed in a reaction helps in determining the stoichiometry for subsequent treatment steps, such as neutralization or recovery, ensuring that the process remains efficient and environmentally safe. Understanding how to interpret chemical formulas and balanced equations is the foundation for such precise industrial applications.