CHEA 1201L PreLab for Gravimetric Analysis.docx - Danica...

Danica Kaye V. Monteza Group 1 CHEA
1201L
BS ChE – Year 1 Block A T 10:30 AM –
1:30 PM
CHEA 1201 L
Gravimetric Analysis of Sulfur
Pre-laboratory Activity
1. What is gravimetry? Enumerate the 5-6 steps in the gravimetric
analysis. (3 pts)

STEP 6. Computation of the amount of the particular
constituent in the sample from the observed weight of the
isolated substance.
2. What are the three types of gravimetric analysis? Provide a brief
description for each. (3 pts)
3. Provide the balanced chemical equations for the following: (2 pts)
a. Reaction of sodium sulfate and barium chloride
b. Reaction of sodium chloride and silver nitrate
4. Calculate the number of moles of each reactant in the Procedure
(see steps 2 and 4).
a. identify the limiting reactant in the reaction and

b. determine the theoretical amount of barium sulfate that
should be produced. (3 pts)
5. Suppose that 0.323 g of an unknown sulfate salt is dissolved in 50
mL of water. The solution is acidified with 6 M HCl, heated, and an
excess of aqueous BaCl2 is slowly added to the mixture resulting in
the formation of a white precipitate.
a. Assuming that 0.433 g of precipitate is recovered
calculate the percent by mass of SO
4
2−
in the unknown
salt. (2 pts)
Asked:
The percent by mass of SO
4
2− in the unknown salt assuming that 0.433
g of precipitate is recovered