# Lesson Worksheet: Precipitation Gravimetry Chemistry

In this worksheet, we will practice determining the mass or composition of an analyte using precipitation gravimetry.

Q1:

A 2.45 g sample of white crystals is known to contain and . The sample is fully dissolved in deionized water and an excess of is then added, forming a precipitate of . Upon being filtered, washed, and dried, the precipitate is found to have a mass of 1.54 g. To the nearest integer, what is the percentage by mass of in the mixture?

Q2:

A chemist wants to determine the mass of calcium chloride present in an aqueous solution. Upon the addition of excess silver nitrate, a precipitate was seen to form. After filtration and drying, the mass of the precipitate was found to be 0.85 g .

What is the equation for the reaction between calcium chloride and silver nitrate?

• A
• B
• C
• D
• E

What is the mass of calcium chloride in the original solution? Give your answer to 2 decimal places.

Q3:

A magnesium halide salt has the formula . A 0.593 g sample of was dissolved in 100 mL of deionized water, followed by the addition of excess . The precipitate of was filtered, washed, and dried. The precipitate was found to have a mass of 0.187 g. What is the identity of ?

• A
• B
• C
• D

Q4:

Consider the following reaction:

By which of the following methods are the reaction products separated?

• AFiltration method
• BCrystallization method
• CVolatilization method
• DTitration method
• EDistillation method

Q5:

Fill in the blank: We can separate the precipitate formed from a solution by filtration using .

• Aa buret
• Bashless filter paper
• Ca tube
• Da funnel
• Ean ignition crucible

Q6:

In the precipitation method, why do we use ashless filter paper in chemical analysis?

• ABecause it filters the precipitate from the solution efficiently
• BBecause we know its mass, so we can calculate the mass of the precipitate easily
• CBecause it is affordable
• DBecause it is completely ignited without leaving ash

Q7:

Which of the following choices shows the correct numerical order of the steps of the experiment of quantitative analysis using the precipitation method?

1. Mix the substances together to yield the precipitate.
2. Transfer the precipitate to an ignition crucible and completely ignite.
3. Isolate the precipitate by using ashless filter paper.
4. Weigh the mass of the remaining precipitate.
• A1, 4, 2, 3
• B1, 2, 4, 3
• C1, 4, 3, 2
• D1, 3, 2, 4
• E1, 2, 3, 4

Q8:

What is meant by the precipitation method?

• AIt is a type of gravimetric analysis that is based on the heating of the element or compound and determining its mass by measuring the amount lost from the original mass of the substance.
• BIt is a type of volumetric analysis that is based on the precipitation of the analyte in the form of a pure, sparingly soluble compound with a constant and known chemical structure.
• CIt is a type of gravimetric analysis that is based on the precipitation of the analyte in the form of a pure, sparingly soluble compound with a constant and known chemical structure.
• DIt is a type of volumetric analysis that is based on the precipitation of the analyte in the form of insoluble crystals.

Q9:

Consider the equation

From the equation, what is the mass of when 5 g of precipitates? Give your answer to one decimal place.

Q10:

When we mix silver nitrate and potassium chloride together, a white precipitate of silver chloride forms. Calculate the mass of potassium chloride when 2 g of silver chloride is precipitated. Give your answer to 2 decimal points.

This lesson includes 18 additional questions and 24 additional question variations for subscribers.