Experiment 6E
Predicting and Measuring the Mass of a Reactant in Excess
Block: E
Date: January 27, 2016
Purpose
The purpose of this lab is to help us review writing and balancing an equation, applying principals of stoichiometry, predicting amount of zinc's excess and analyze experimental results to determine unexpected results.
Materials
Refer to Health Lab Experiment, Lab 6E, page 93
Procedures
Refer to Health Lab Experiment, Lab 6E, page 93-94
* We only used 25 ml of 1.5 M HCl instead of filling the buret with 1.5 M HCl
Data and Observations
Part 1
Mass of test tube – 19.445g
Mass of test tube and zinc – 21.000g
Initial reading of 1.50 M HCl – 25.00mL
Last reading of 1.50 M HCl – 38.45mL
Mass of test tube and zinc after decanting, washing, and drying - 20.251g
Observations of test tube containing Zn after addition of HCl
Produced gas
Turned white/cloudy and milky
Slow reaction turned faster
Little bubbles sizzle in the tube
Zn slowly turned grey
After the reaction turned clear
Reacted Zn turned dark grey
Unreacted Zn remain its irony color
Part 2
Mass of test tube and zinc – 20.251g
Results
The excess of zinc is different from different calculations by 0.2g. We’ve got 0.6g of Zn using stoichiometry calculations and on the other hand, we’ve got 0.806 g of Zn through the use of experimentally measurement.
Discussion