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Acids and Bases

Investigation 2 – PostLab

 

 

 

 

 

 

 

ANALYZE IT

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

Draw a graph that compares the pH of the solutions and the number of times you diluted the original solution of HCl. Use the data from Table A to draw the graph.

  • What solvent did you use to dilute your solutions as you performed your serial dilutions?
  • Look at the solutions in the centrifuge tubes. As you diluted the original red solution of hydrochloric acid (HCl), what happened to the red color of the hydrochloric acid (HCl)? Which solutions displayed a shade of red or pink and which solutions were colorless? 
  • Based on your observations of the color of the solutions, what happened to the concentration of the red food coloring when you diluted the original red solution of hydrochloric acid (HCl)? 
  • What other solutes in addition to the food coloring were you diluting and measuring as you performed your serial dilutions? 
  • From the data in Table A, what was the pH of the undiluted HCl? 
  • Look at your graph. As the undiluted hydrochloric acid (HCl) was diluted from 1 to 5 times with water, what happened to the pH? 
  • Inspect your graph. As the original hydrochloric acid (HCl) was diluted from 1 to 5 times with water, what happened to the hydrogen ion (H+) concentration? 
  • Look at Table A. Solution 1 was how many times less concentrated than the hydrochloric acid (HCl)? How could you use a decimal to show this change? 
  • Look at Table A. Solution 2 was how many times less concentrated than the original solution of HCl? How could you use a decimal to show this change?
  • Each solution was how many times less concentrated than the previous one? 

GET FOCUSED

Complete the Focus Question in your SDR then discuss it as a class. 

  • What is the relationship between the pH of a solution and the concentration of hydrogen ions (H+)?