rq pratical temp changes

• What should you be able to describe by the end of the video on temperature changes in chemical reactions?

  How to investigate the variables that affect temperature changes in chemical reactions
• What type of reaction is being investigated in this practical?

  Exothermic reaction
• What is the neutralization reaction being studied in this experiment?

  The reaction between hydrochloric acid and sodium hydroxide
• What is the independent variable in this experiment?

  The volume of sodium hydroxide solution
• What is the dependent variable in this experiment?

  The maximum temperature reached
• What are the control variables in this experiment?

  The volume of hydrochloric acid and the concentrations of both solutions
• How do you prepare the hydrochloric acid for the experiment?

  Measure 30 centimeters cubed of dilute hydrochloric acid
• Why do we place the polystyrene cup inside a beaker?

  To prevent the cup from falling over
• What should you do after adding sodium hydroxide solution to the polystyrene cup?

  Fit a plastic lid and place the thermometer in the solution
• What happens to the temperature of the solution during the exothermic reaction?

  The temperature of the solution increases
• When do you record the highest temperature reached in the experiment?

  When the reading on the thermometer stops changing
• What is the procedure after measuring the temperature for the first volume of sodium hydroxide?

  Repeat the experiment using 10 centimeters cubed of sodium hydroxide solution
• How do you determine the mean value for the maximum temperature reached?

  By calculating the average of two sets of results
• What trend is observed as the volume of sodium hydroxide solution increases?

  The maximum temperature reached increases
• Why does the maximum temperature start to decrease after a certain volume of sodium hydroxide?

  There is not enough hydrochloric acid for all the sodium hydroxide to react
• What happens to the energy released when large volumes of sodium hydroxide are added?


  The energy is spread out into a greater volume
• Why is a polystyrene cup with a lid used in this experiment?

  To reduce heat losses during the temperature measurement
• Where can students find more questions on this required practical?

  In the vision workbook linked in the video
• What is the role of polystyrene as a material in this experiment?

  It is a good thermal insulator
• What is the procedure for measuring the temperature change in an exothermic reaction?

  Measure the temperature before and after adding sodium hydroxide to hydrochloric acid
• Why is a thermometer significant in the experiment?

  It measures the temperature changes during the reaction
• Why is it important to repeat the experiment multiple times?

  To ensure accuracy and reliability of results
• What concept explains the energy release in exothermic reactions?

  Energy is released when reactants form products
• How does the concentration of reactants affect temperature change?

  Higher concentrations lead to greater temperature changes
• Why is recording data in a table format important?

  It helps organize and analyze the results effectively
• What effect does reaction volume have on temperature change?

  Increased reaction volume can lead to decreased maximum temperature
• What is the concept of neutralization in chemistry?

  The reaction between an acid and a base to form water and salt