Who’s been cheating on the vinegar? Aim: To investigate if the vinegars have been diluted by working out their concentrations. Scientific Background: Vinegar is an acid and there fore can be neutralised by an alkali. Acid + Alkali ‘a salt + water Hydrochloric acid + Sodium Hydroxide ‘a Sodium chloride + water Vinegar is a weak acid and therefore it only partially ionizes in solution. CH 3 COOH ss’a CH 3 COO- + H+An alkali such as Sodium Hydroxide has a formula NaOH. If the alkali is strong then it ionizes fully in solution. NaOH ss’a Na+ + OH-When the acid H+ reacts with the alkali OH- the solution neutralise’s.
Prediction: If the acid has been diluted there will be less H+ ions present in the volume used. Therefore to cancel the alkali more acid will be required. This is on the assumption that the alkali volume and concentration stay constant. Method: . Measure 10 cm 3 of 0.
1 m alkali into a measuring cylinder then place the solution into a 75 cm 3 conical flask… Then add 2-3 drops of indicator to the alkali (it will go purple in colour).
Measure out 50 cm 3 of the vinegar into a measuring cylinder and then place into a glass beaker… Then using a dropper add the vinegar drop wise to the alkali until 1-drop changes the solution to colourless… Replace the vinegar back into the measuring cylinder and record the volume of vinegar used… Repeat this process twice more, recording results…
The Essay on Strong Acid Solution Khp Point
Introduction The two types of aqueous solutions in chemistry that are being experimented with are called acids and bases. A strong acid solution is one that consists of a solution that is less than seven ph factor. The basic solution is one that consists of greater than seven on the ph scale. In this experiment standardization of a chemical reaction is used to determine the concentration of the ...
Then repeat the whole procedure for each different concentration of vinegar. Preliminary Work: Aim: – To find out which concentration of alkali will give accurate, measurable values. Concentration (M) Volume of acid (cm 3) 0. 1 m 21.
45 cm 30. 5 m 78. 9 cm 30. 75 m 100+cm 31. 0 m 100+cm 32.
0 m 100+cm 3 We decided from the results that the best measurable concentration of alkali would be the 0. 1 m concentrations. Investigation: Test 1 Test 2 Test 3 Average Manufacturers’ 10. 27 cm 3 10. 3 cm 3 9. 73 cm 3 10.
11 cm 3 Shop 1 10. 3 cm 3 9. 5 cm 3 10. 25 cm 3 10. 11 cm 3 Shop 2 18. 4 cm 3 17.
9 cm 3 18. 4 cm 3 18. 23 cm 3 Shop 3 40. 1 cm 3 38. 45 cm 3 35. 7 cm 3 38.
08 cm 3 Analysis: These results show that the vinegar from Shop 2 and Shop 3 have been significantly diluted with water or some other substance. The results obtained from shop 1 show that its is very similar in concentration to the manufacturers’. Two of the results show that it is less concentrated than the manufacturers’, but one shows that it is more concentrated, this is impossible so its is most likely due to human error and not taking the readings properly. Concentrations: Manufacturers’ = 1, 10. 11 = 0. 0989119683 Shop 1 = 1, 10.
11 = 0. 0989119683 Shop 2 = 1, 18. 23 = 0. 054854635 Shop 3 = 1, 38. 08 = 0. 026260504 These results show an obvious difference in the concentration with the manufacturers’ being the most concentrated and shop 3’s being the least concentrated.
Evaluation: The results from this experiment can be considered reasonably accurate we took the results quite accurately. The procedure that we used was the same throughout, we put 10 cm 3 of 0. 1 m alkali into a conical flask by using a pipette and a pipette bulb, then got we filled a burette with acid. We then added some indicator to the alkali and it turned purple, after that we slowly added acid to the alkali while stirring and waited until the solution turned colourless and took a reading from the burette. There was one error we found when doing the experiment and that was when shop 1 was more concentrated which is impossible because it could not be more concentrated then the manufacturers’.
The Essay on To investigate the effect to the potato cells in the different solute concentration water
Water can move through the different cells due to the difference of water potentials in the cells. If there is a higher solute concentration in the cell than outside the cell, the water will move into the cell. However, if the concentration of inside the cell is lower than the outside, water will not move into the cell. This process is called osmosis. Research question; This investigation will ...
This could be down to a number of things such as human error; by not taking the reading at the exact time or that the alkali / acid became contaminated. To improve the accuracy of the results we could have done the experiment more times and made sure that there were no mistakes.
