Question

11 select the correct answer. identify the number of moles in 369 grams of calcium hydroxide. use the periodic table and the polyatomic ion resource. a. 3.23 moles b. 4.98 moles c. 6.35 moles d. 6.46 moles e. 8.98 moles

Explanation:

Step1: Find molar mass of Ca(OH)₂

Calcium (Ca) has molar - mass 40.08 g/mol, oxygen (O) has molar - mass 16.00 g/mol, and hydrogen (H) has molar - mass 1.01 g/mol. In Ca(OH)₂, there is 1 Ca, 2 O, and 2 H.
$M = 40.08+(2\times16.00)+(2\times1.01)=40.08 + 32.00+2.02=74.10$ g/mol

Step2: Calculate number of moles

Use the formula $n=\frac{m}{M}$, where $m = 369$ g and $M = 74.10$ g/mol.
$n=\frac{369}{74.10}\approx4.98$ moles

Answer:

B. 4.98 moles