Featured in PASCO’s Chemistry through Inquiry Teacher Guide

Chemistry through Inquiry Teacher Guide


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


Lab Summary

Use a temperature sensor to determine the mole ratio between the reactants sodium hypochlorite and sodium thiosulfate.


Determine the mole ratio between the reactants sodium hypochlorite and sodium thiosulfate. Through this investigation, students:

  • Review the evidence of chemical reactions.
  • Describe the connection between coefficients in chemical reactions and the amount of product formed.
  • Explain the term limiting reactant.



Students conduct the following procedures:

  • React sodium hypochlorite and sodium thiosulfate in various proportions and measure the resulting temperature changes.
  • Analyze data to determine the optimal mole ratio between the two reactants.
  • Determine the limiting reactant for specified reaction variations.

Sensors / Equipment Used:

PASPORT Chemistry Sensor


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

Materials Used:

Graduated cylinder, 10-mL - 2
Graduated cylinder, 50- or 100-mL - 2
Transfer pipet - 2
Test tube, 20-mm × 150-mm - 7
Test tube rack 
Wash bottle filled with water 
Waste container 
0.5 M Sodium hypochlorite - 35 to 40 mL
0.5 M Sodium thiosulfate, in 0.2 M sodium hydroxide - 35 to 40 mL

Your Bundle Options:

Option 1:

Chemistry Starter Sensor Bundle


A sensor bundle specifically designed to get you started using probeware in your chemistry lab. Also: perform 22 Lab Activities from Chemistry through Inquiry teacher guide.

Option 2:

Chemistry Standard Sensor Bundle


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.