Percent Composition of Magnesium Sulfate Heptahydrate

The video tutorial explains how to calculate the percent composition by mass of water in magnesium sulfate heptahydrate. It begins by finding the molar mass of magnesium sulfate and the water molecules, then combines them to get the molar mass of the entire compound. Using this information, the tutorial demonstrates the formula to calculate the percent composition, resulting in 51.17% of the compound's mass being due to water. The video concludes by emphasizing the significance of this percentage.

What is the first step in finding the percent composition by mass for water in magnesium sulfate heptahydrate?

• Measure the volume of the compound.

• Find the density of the compound.

• Determine the number of water molecules.

• Calculate the molar mass of magnesium sulfate.

What is the molar mass of the entire magnesium sulfate heptahydrate compound?

• 246.51 grams per mole

• 98.07 grams per mole

• 120.37 grams per mole

• 18.02 grams per mole

How many water molecules are present in magnesium sulfate heptahydrate?

• Five

• Six

• Seven

• Eight

What is the molar mass of water used in the calculation?

• 18.02 grams per mole

• 20.18 grams per mole

• 15.99 grams per mole

• 22.04 grams per mole

Why does the grams per mole unit cancel out in the percent composition formula?

• Because it is a constant value.

• Because it appears in both the numerator and the denominator.

• Because it is not needed in the calculation.

• Because it is a variable.

What is the percent composition of water in magnesium sulfate heptahydrate?

• 55.89%

• 51.17%

• 60.12%

• 45.23%

What does the percent composition result indicate about the compound?

• The compound is mostly magnesium sulfate.

• The compound is mostly water.

• The compound has no water.

• The compound is equally water and magnesium sulfate.