Calculate the molar mass of calcium hydroxide.
Understand the Problem
The question is asking for the calculation of the molar mass of calcium hydroxide (Ca(OH)₂). This involves adding the atomic masses of each component in the compound: calcium (Ca), oxygen (O), and hydrogen (H).
Answer
$74.10 \, \text{g/mol}$
Answer for screen readers
The molar mass of calcium hydroxide (Ca(OH)₂) is $74.10 , \text{g/mol}$.
Steps to Solve
- Identify the atomic masses First, we need to find the atomic masses of calcium, oxygen, and hydrogen.
- Calcium (Ca) has an atomic mass of approximately $40.08 , \text{g/mol}$.
- Oxygen (O) has an atomic mass of approximately $16.00 , \text{g/mol}$.
- Hydrogen (H) has an atomic mass of approximately $1.01 , \text{g/mol}$.
- Determine the number of each atom in Ca(OH)₂ In the compound calcium hydroxide, we have:
- 1 calcium atom
- 2 hydroxide ions (OH), which means 2 oxygen atoms and 2 hydrogen atoms.
- Calculate the contribution of each component Now, we'll calculate the mass contributed by each component in the compound.
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For calcium: $$ \text{Mass of Ca} = 1 \times 40.08 , \text{g/mol} = 40.08 , \text{g/mol} $$
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For oxygen: $$ \text{Mass of O} = 2 \times 16.00 , \text{g/mol} = 32.00 , \text{g/mol} $$
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For hydrogen: $$ \text{Mass of H} = 2 \times 1.01 , \text{g/mol} = 2.02 , \text{g/mol} $$
- Add all contributions together Finally, we sum all the contributions to find the molar mass of calcium hydroxide: $$ \text{Molar Mass of Ca(OH)}_2 = 40.08 + 32.00 + 2.02 = 74.10 , \text{g/mol} $$
The molar mass of calcium hydroxide (Ca(OH)₂) is $74.10 , \text{g/mol}$.
More Information
The molar mass is useful in stoichiometric calculations in chemistry, such as determining how much of a substance is needed for a reaction or how much product will be formed. Calcium hydroxide, commonly known as slaked lime, is used in various applications including water treatment and as a building material.
Tips
- Forgetting to multiply the atomic mass by the number of atoms for each element in the compound can lead to incorrect results.
- Mixing up the number of atoms in hydroxide (OH) ions; remember there are 2 oxygen and 2 hydrogen atoms per formula unit of Ca(OH)₂.
