To find out how many grams of bromine are used in the reaction, we can use the principle of the conservation of mass. This principle states that the mass of the reactants must equal the mass of the products in a chemical reaction.
Here's a step-by-step solution:
1. Identify the masses involved in the reaction:
- The mass of calcium ([tex]\( \text{Ca} \)[/tex]) is 12 grams.
- The mass of calcium bromide ([tex]\( \text{CaBr}_2 \)[/tex]) is 25 grams.
2. Understand the conservation of mass:
- The total mass of the reactants equals the total mass of the products.
3. Set up the equation based on the conservation of mass:
- Let [tex]\( m_{\text{Br}_2} \)[/tex] represent the mass of bromine ([tex]\( \text{Br}_2 \)[/tex]).
- According to the conservation of mass:
[tex]\[
\text{Mass of Ca} + \text{Mass of Br}_2 = \text{Mass of CaBr}_2
\][/tex]
[tex]\[
12 \text{ g} + m_{\text{Br}_2} = 25 \text{ g}
\][/tex]
4. Solve for the mass of bromine:
- Isolate [tex]\( m_{\text{Br}_2} \)[/tex] by subtracting the mass of calcium from the mass of calcium bromide.
[tex]\[
m_{\text{Br}_2} = 25 \text{ g} - 12 \text{ g}
\][/tex]
[tex]\[
m_{\text{Br}_2} = 13 \text{ g}
\][/tex]
So, the mass of bromine used in the reaction is [tex]\( 13 \)[/tex] grams.
