What is the percent by mass of oxygen in Ca (OH) 2?

The answer to your question is Percent by mass = 43.2

Explanation:

Data

Ca (OH) ₂

Percent by mass of Oxygen = ?

Process

1. - Calculate the molecular mass of Ca (OH) ₂

Ca (OH) ₂ = (40 x 1) + (16 x 2) + (2 x 1)

= 40 + 32 + 2

= 74 g

2. - Calculate the mass of Oxygen = (16 x 2)

= 32 g

3. - Calculate the percent by mass

Percent by mass = (mass of oxygen/mass of Ca (OH) ₂) x 100

Percent by mass = (32/74) x 100

Percent by mass = 43.2