74g of calcium hydroxide will yield OH ions:
Correct answer: B. 34g
- A. 178
- B. 34g
- C. 51g
- D. 40g
Explanation
74g of Ca(OH)2 equals 1 mole since the molar mass is 74 g/mol. The dissociation of Ca(OH)2 produces 2 moles of OH ions for every mole of Ca(OH)2. Each OH ion has a molar mass of 17g/mol, so 2 moles produce 34g of OH ions (17g/mol x 2). Thus, the correct answer is 34g. Options 178g, 51g, and 40g do not match the stoichiometric calculation for the amount of hydroxide ions produced from the dissociation of 74g of Ca(OH)2.
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