Student Portal:

Chemical Reactions

Investigation 2 – PostLab

 

 

 

 

 

 

 

ANALYZE IT

When you have finished your Investigation, discuss the data in Table C.

Note: For each Trial, you should use the measured diameter of the inflated balloon to calculate the volume of hydrogen gas produced.

Refer to the Analysis section in your Student Data Record for instructions on using the formula for the volume of a sphere.

Note: You should calculate the volume of the inflated balloon for every Trial and enter the volumes in Table C.

Complete the analysis of your data by graphing your data from Table C in your SDR using the procedure for Graphing of Independent and Dependent Variables found in your Procedural Toolbox if necessary.

Note: You should connect the data points for Trials 1 through 5 with straight lines and not draw a best fit line.

Note: Also, you should plot the data point from Trial 6 and not draw a line through it.

 

Analyze the graph in the range of hydrochloric acid volumes between 2 and 50 ml then answer the questions in problems 3 and 4 of the Analysis section in your Student Data Record.

  • What is the relationship between the volume of hydrochloric acid added as a reactant and the volume of hydrogen gas (H2) that was produced as a product?
  • In this range of hydrochloric acid volume, do you think that the hydrochloric acid or the magnesium is greater in amount? Why? 

Analyze the graph in the range of hydrochloric acid (HCl) volumes between 50 and 100 ml then answer the questions in your Student Data Record.

  • What is the relationship between the volume of hydrochloric acid added as a reactant and the volume of hydrogen gas that was produced as a product? 
  • In this range of volumes of hydrochloric acid, do you think that the hydrochloric acid or the magnesium is greater in amount? Why? 

Read the Background in your Student Data Record and discuss the case where one reactant is present in a greater amount than the other.

What about a chemical reaction in which one reactant remains unreacted. Answer these questions in your Student Data Record.

  • If one of the reactants is completely consumed but some of the second reactant remains unreacted, which reactant limits the amount of products that can be produced? Why? 
  • Analyze the graph in the range of hydrochloric acid volumes between 50 and 100 ml. Why did the diameter of the balloon and the volume of hydrogen gas remain unchanged in this range of hydrochloric acid volumes? 

Analyze the graph for the two data points for the reactions of 0.5 g of magnesium and 1 g of magnesium metal with 100 ml of hydrochloric acid. Answer the questions in your Student Data Record.

  • Compare the volume of hydrogen produced by the reactions of 0.5 g and 1 g of magnesium with 100 ml of hydrochloric acid. Which reaction produced a greater volume of hydrogen H2? 
  • Why did one reaction produce more hydrogen H2 gas than the other? 
  • In the reaction of 100 ml of hydrochloric acid and 0.5g of magnesium, which reactant was present in the lesser amount? 
  • What are the two products of the chemical reaction that you have observed?

Based on the data collected in the Investigation, answer the following questions, and compare your conclusions with your predicted answers.

  • Are the reactants always completely used up in a chemical reaction? 
  • Does the matter making up the reactants disappear? 
  • What happens if there is more of one reactant than the other reactant? 
  • How do you know when a chemical reaction has stopped? 

GET FOCUSED

Complete the Focus Questions in your SDR then discuss them as a class. 

  • In a chemical reaction, do the amounts of the reactants affect the amounts of products produced?

  • How does the Law of Conservation of Matter relate to chemical reactions?