Featured in PASCO’s Chemistry through Inquiry Teacher Guide

Chemistry through Inquiry Teacher Guide

(PS-2871C)

Features over 25 inquiry based labs covering the fundamental concepts of lab skills, structure & properties of matter, chemical reactions and more.

Molar Mass of Copper

Lab Summary

Use a voltage-current sensor to determine the molar mass of copper through electroplating in an electrolytic cell.

Theory

Determine the molar mass of copper through electroplating in an electrolytic cell. Through this investigation, students:

  • Differentiate between oxidation and reduction.
  • Use the area under a curve to provide meaningful data.
  • Convert current (amperes) to moles of electrons using the Faraday constant.
  • Use stoichiometric calculations.

Method

Students conduct the following procedures:

  • Electroplate an object with copper.
  • Determine the mass of deposited copper by finding the difference between the mass of the object before and after it is plated.
  • Determine the number of electrons transferred during electroplating from the area under the curve of a Current versus Time graph.
  • Use stoichiometry and the number of electrons transferred to determine the number of moles of copper reduced.
  • Calculate the molar mass of copper by dividing the mass of copper plated by the moles of copper determined experimentally.

Sensors / Equipment Used:

PASPORT Chemistry Sensor

(PS-2170)

Allows students to measure Temperature, pH/ISE/ORP, Absolute Pressure & Voltage in one sensor. For use with PASPORT Interfaces.

Materials Used:

Balance, centigram 
Beaker, 250-mL 
Utility clamps, insulated - 2
Ring stand 
Magnetic stirrer 
DC power supply 
Black patch cord, 4-mm banana plug
Copper electrode 
Stainless steel spoon (or other item to electroplate) 0.5 M Copper(II) sulfate - 150 mL

The Associated Bundle:

Chemistry Standard Sensor Bundle

(PS-2927C)

Contains the sensors and probes needed to perform all 17 experiments in the Advanced Chemistry Teacher Guide and all 25 labs in the Chemistry through Inquiry Guide.

Interface Required

This experiment may require software and an interface for data collection.