Investigating the Properties of Ph

Investigating the Properties of pH
The manufacture’s claim is that Sensodyne toothpaste micro hardens tooth enamel to help protect against the effects of acid wear, helps stop the twinges of pain from sensitive teeth formulated with low abrasivity, neutral pH and gentle yet effective cleaning system.

To find out if the manufactures claim on Sensodyne toothpaste is the correct level of pH. I expect the Sensodyne toothpaste to be a neutral pH level as the manufactures claim that this products pH level is neutral. This would be indicated by a level of pH 6 and 7.

The equipment needed for this practical * Sensodyne (toothpaste) * Universal indicator * Universal paper * pH meter * Petri dish x 3 * Measuring cylinder x 6 * Wooden stick * Distilled water * Tap water * Ruler

Method 1. Test the distilled water and tap water for the pH level to see if it were neutral so it wouldn’t make a difference to the results. 2. Set up 3 petri dishes and 3 measuring cylinders 3. Measure 10mls of tap water. Add water to the petri dish and add 5cm of Sensodyne (toothpaste) into each petri dish and repeat this step 3 times. 4. Measure 10mls of distilled water and add to the measuring cylinders as well as adding 5cm of Sensodyne (toothpaste) and repeat this step 3 times.

5. Mix the substances together with the wooden stick. 6. Put universal indicator (liquid) into the petri dish repeat this step 3 times. Record the results from each petri dish. 7. Put universal indicator (paper) into the measuring cylinder repeat this step 3 times Record the results from each measuring cylinder. 8. Set up pH meter, Put the pH meter into the measuring cylinder record the pH reading and repeat this step 3 times for a reliable.

Results Table

Universal Indicator Universal Paper pH Meter

Test 1 pH6 6 7.30

Test 2 pH6 6 6.99

Test 3 pH6 6 7.09

Photographic evidence of experiments Before: After:

Before: After:

Discussion * The results show pH of the toothpaste is neutral according to the pH meter, and slightly acidic according to the paper and indicator. The pH was discovered to be between 6 and 7 in all the tests done * The manufacturers’ claim was the pH level of the sensodyne (toothpaste) was neutral. My hypothesis was that the toothpaste was pH neutral and this was supported by the results. * I compared distilled water and tap water because of the different chemicals mixed with the water, but the results showed no difference so it didn’t affect the pH. The pH meter showed little varying but not too much this could be that the pH meter is out or that there could be something wrong with the meter because with my supported evidence its unlikely to be wrong. To improve this experiment would be to test with more than one pH meter to see if there’s a difference in comparison. Otherwise it may be more efficient if there were more tests done for more support towards the result. * My independent variable is the sensodyne (toothpaste) because in every experiment I used the same amount of sensodyne. The dependant variable was the pH levels were I did not have control over what the pH level would indicate. This is the reason the results are reliable because I repeated the steps three times in each test and continued to get the same results. This experiment could be improved by obtaining samples of toothpaste from a variety of locations. This will identify and inconsistency’s in the product itself.

Conclusion * The experiment found that the manufactures claim of pH is correct and it is a neutral pH with supported evidence. Teeth would be affected by acidic toothpaste or alkaline toothpaste. Therefore a pH between 6 and 7 is an appropriate toothpaste .This sensodyne (toothpaste) is designed to help people with sensitive teeth.