Yes, when balancing a chemical equation, you can add coefficients in front of the compounds or elements in the equation. The goal is to ensure that there are equal numbers of each type of atom on both sides of the equation, in accordance with the law of conservation of mass.
Here's a step-by-step guide to balancing a chemical equation:
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Write the Unbalanced Equation: Start with the unbalanced equation. For example, for the reaction of hydrogen and oxygen to form water, you would write: \[ \text{H}_2 + \text{O}_2 \rightarrow \text{H}_2\text{O} \]
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Count Atoms of Each Element: Count how many atoms of each element are present on both sides of the equation. In the example:
- Reactants: 2 H (from H₂) and 2 O (from O₂)
- Products: 2 H (from H₂O) and 1 O (from H₂O)
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Add Coefficients: Start balancing one element at a time by adding coefficients. It’s often easiest to start with the most complex molecule. For our example, you might place a coefficient of 2 in front of H₂O: \[ \text{H}_2 + \text{O}_2 \rightarrow 2 \text{H}_2\text{O} \] Now recount:
- Reactants: 2 H and 2 O
- Products: 4 H (from 2 H₂O) and 2 O (from 2 H₂O)
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Adjust Coefficients as Necessary: You can add or modify coefficients as needed to balance the equation. In this case, we need to adjust H₂ as well: \[ 2 \text{H}_2 + \text{O}_2 \rightarrow 2 \text{H}_2\text{O} \]
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Check Your Work: Finally, confirm that the number of atoms for each element is the same on both sides of the equation.
The balanced equation is: \[ 2 \text{H}_2 + \text{O}_2 \rightarrow 2 \text{H}_2\text{O} \]
Remember, you can only change the coefficients, not the subscripts within the chemical formulas, as changing subscripts would change the identity of the compounds.