Table of Contents
Titration of Na₂CO₃ with HCl
The titration of Na₂CO₃ with HCl is a process by which the concentration of HCl in a solution is determined by measuring the volume of HCl needed to completely react with a known concentration of Na₂CO₃. The process begins by adding a small amount of HCl to a solution of Na₂CO₃, and then measuring the pH of the solution. The pH of the solution will decrease as HCl is added, as HCl is a strong acid. Once the pH of the solution reaches a certain point, the addition of more HCl will not cause the pH to decrease any further. This point is known as the endpoint of the titration. The volume of HCl added at the endpoint is used to calculate the concentration of HCl in the original solution.
Aim
The aim of this study was to investigate the effects of a two-month sprint interval training programme on aerobic fitness, body composition and markers of insulin resistance in overweight and obese young adults.
Background
There is a growing body of evidence to suggest that sprint interval training (SIT) may be an effective means of improving aerobic fitness and body composition in overweight and obese adults. However, the effects of SIT on markers of insulin resistance in this population are unknown.
Methods
In this randomised controlled trial, overweight and obese young adults (n=27) were randomly assigned to either a SIT or a control group. The SIT group undertook a two-month SIT programme, consisting of three sessions per week. The control group undertook no intervention. Aerobic fitness, body composition and markers of insulin resistance were assessed pre- and post-intervention.
Results
The SIT group showed a significant improvement in aerobic fitness (p<0.001) and a reduction in body fat percentage (p<0.001) post-intervention. There was no significant change in markers of insulin resistance post-intervention. Conclusion This study provides evidence that a two-month SIT programme can improve aerobic fitness and body composition in overweight and obese young adults. However, the effects of SIT on markers of insulin resistance in this population are unknown.
Theory
of mind
Theory of mind is the ability to attribute mental states – beliefs, intents, desires, etc. – to oneself and others, and to understand that others have beliefs, desires, and intentions that are different from one’s own. It is the capacity to imagine what someone else is thinking or feeling.
Materials Required
To make a paper airplane you will need some paper, a ruler, and a knife or scissors.
Procedure for Titration of HCl and Sodium Carbonate
A titration is a laboratory procedure used to determine the concentration of a substance in a solution. In this experiment, you will titrate a solution of hydrochloric acid (HCl) with a solution of sodium carbonate (Na2CO3).
1. To begin, measure out 25.00 mL of 0.100 M HCl using a graduated cylinder.
2. Next, measure out 25.00 mL of 0.100 M Na2CO3 using a graduated cylinder.
3. Pour the Na2CO3 solution into a clean Erlenmeyer flask.
4. Add a few drops of phenolphthalein indicator to the solution.
5. Place the Erlenmeyer flask on a balance and record the weight.
6. Titrate the Na2CO3 solution with the HCl solution using a burette.
7. When the solution turns pink, stop titrating and record the final volume.
8. Calculate the concentration of the HCl solution.
