Analía Bellizzi – Chemistry Classes

Ronald Reagan Senior High School

Rates of Reaction Lab #1 HCl+Mg

Rates of Reaction Lab

Items to show in the LAB REPORT

  • 1- TITLE
  • 2- LAST AND FIRST NAME OF MEMBERS
  • DATE
  • PURPOSE OF THE LAB (How the temperature affects the rate of a reaction)
  • MATERIALS
  • DATA TABLES: Data tables must be built  WITH RULERS, using units ONLY ON THE HEADER. (Do not repeat the unit in every row)
  • Graphs & Charts MUST BE AS FOLLOWS
    • In graph paper.
    • with LABELLED AXES AND UNITS
    • TIME MUST BE ON X AXIS
    • VOLUME MUST BE ON Y AXIS
    • using ruler
    • scale must be uniform (the distance between the same quantities must be represented by the same distance.
    • line graphs ONLY will be accepted
    • DO NOT CONNECT THE DOTS one by one, draw a smooth line touching as many dots as possible
  • Least squares fit
  1.  

Watch the following video and then complete materials and procedures  and lab setup in your lab notebook:

  1. The purpose of this lab is: (You complete it)
    …………………………………………………………………………………………………………………..

Materials

  1. Beaker with HCl solution 1M (you will need around 100 cm3)
  2. Ring Stand and clamp
  3. 100 cm3 graduated cylinder
  4. 50 cm3 graduated cylinder
  5. Delivering tube with rubber stopper
  6. Timer or camera with timer.
  7. 5 cm of Mg ribbon (around 0.085 g)

Procedures

  1. Prepare the apparatus as the one in the picture.
  2. Place 50 cm3 HCl 1M in the flask. Measure the temperature.
  3. Prepare your timer
  4. Prepare your camera (You can use your cellphone)
  5. Place 5 cm of Mg ribbon in the flask and cover the flask immediately.
  6. Record the volume of gas produced every 5 seconds until you do not have any more gas delivered. (you can use your camera and play it back to obtain your measurements)
  7. Record your observations besides the gas volume.
  8. Repeat the experiment using  the same volume of HCl at  around 40° instead.

Lab setup (Draw it yourself, do NOT use a picture or copy and paste. Label your lab setup)

Apparatus set-up

 

  1. Data tables (use graph paper)


Time (seconds)

COLD ACID
Volume (cm3)

video #2

HOT ACID
Volume (cm3)

Video #3

 00    
 05    
 10    
 15    
 20    
 25    
 follow with the measurements until the reaction stops for AT LEAST one minute…..    
     
     
     
     
     
     
     
     
     
     
     
     
     
     
  1. Graph
    1. Graph showing the time in the “X” and volume of water displaced by the gas on the “Y” (use graph paper).
    2. Use ONLY ONE GRAPH for both experiments. Mark the values for hot acid using red pen/pencil. Mark values of cold acid using a blue pen/ pencil
    3. Do not connect the dots, draw the line (curve) of best fit. 
  2. Analysis questions

1)      How are the graphs for the cold and hot acid similar?

2)      How are the graphs for the cold and hot acid different?

3)      In which condition you got more gas delivered? How you can explain this?

4)      What can you infer from both experiments?

5)      How would the graph look like if you use acid at 100 ºC? (sketch in a small piece of paper showing your hot and cold acid in red and blue and the prediction in black)

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6)      How would the graph look like if you use acid at 0 ºC? (sketch in a small piece of paper showing your hot and cold acid in red and blue and the prediction in black)

7)      How would the graph look like if you use 2.5 cm of Mg instead of the 5 cm?              (sketch both graphs in one)

8)      What would you expect to see if you use magnesium powder? Why?

9)      What is the gas that was generated in the graduated cylinder? How can you prove it in the lab?

10)    Write the balanced chemical equation for the reaction between HCl and Mg.

11)    How many moles of HCl were present in the 50 mL of 1M solution?

12)    5 cm of magnesium have around 0.085 g of Mg metal. How many moles of Mg. were present in the sample?

13)   Which is the limiting reactant in the reaction produced in the conical flask?

14)   Assuming that at room temperature ONE MOLE of any gas occupies 24 L, which is the expected volume of the H2 gas produced in the reaction?

15)  The amount of gas obtained during the lab is the actual yield. The amount of gas predicted in question #14 is the theoretical yield. With this information, which is the percent yield of the reaction?