“The chemical formula for calcium hydroxide is: Ca (OH) 2 Calculate the molar mass of calcium hydroxide_ Round your answer to 2 decimal places. g ‘ mol X10”
The Correct Answer and Explanation is:
Correct Answer:
The molar mass of calcium hydroxide, Ca(OH)₂, is 74.10 g/mol.
Explanation:
Molar mass is the mass of one mole of a compound, calculated by summing the atomic masses of all the atoms in its formula. For calcium hydroxide, Ca(OH)₂, the calculation involves the atomic masses of calcium (Ca), oxygen (O), and hydrogen (H).
- Calcium (Ca): 1 atom × 40.08 g/mol = 40.08 g/mol
- Oxygen (O): 2 atoms × 16.00 g/mol = 32.00 g/mol
- Hydrogen (H): 2 atoms × 1.01 g/mol = 2.02 g/mol
Adding the individual contributions gives:
40.08 + 32.00 + 2.02 = 74.10 g/mol
This value represents the mass of one mole of calcium hydroxide in grams. The compound contains one calcium ion (Ca²⁺) and two hydroxide ions (OH⁻). Each hydroxide ion consists of one oxygen atom and one hydrogen atom, hence the multiplication of the O and H atomic masses by 2.
Molar mass plays a crucial role in stoichiometry, which involves the calculation of reactants and products in chemical reactions. It serves as a bridge between the number of particles (in moles) and the actual mass used in laboratory or industrial settings. In this case, 74.10 grams of calcium hydroxide corresponds to one mole of the substance.
This value is essential for converting between grams and moles in quantitative chemical analysis. For example, to find out how many moles are in 148.20 grams of calcium hydroxide, divide the mass by the molar mass:
148.20 ÷ 74.10 = 2.00 moles
Such calculations are fundamental in determining the proper proportions of substances involved in reactions to ensure they proceed efficiently and safely.
