PRINT Experiment of 3 Different Acids

 

Water Temperature vs. 3 Different Acids Investigation

Aim: To investigate the effect of the 3 different acids reacting with the bath bomb at room temperature and determine which will inflate the largest balloon.

Hypothesis:If I use 1M Hydrochloric acid, the biggest balloon will be produced.

Risk Assessment and Planning

In this experiment we were dealing with acids and glassware. The acids were extremely easy to spill as well. Wearing safety glasses and aprons ensured our basic safety, and paper towels could be used to mop up any spillage. Broken glass The timer must be kept nearby and be started instantly. All equipment should be located closer to the wall than to the edge of the workbench.

Apparatus:

·        One pre-stretched balloon	·        5 g of either crushed, partly crushed or large pieces of bath bombs	·        Container for holding equipment
·        Equipment to measure weight	·        25 mL of Vinegar (4%) (Acetic Acid)	·        Hydrochloric Acid 1M
·        25 mL of Standard Lemon Juice (Citric Acid)	·        25 mL measuring cylinder	·        100 mL conical flask
·        Timer of some sort	·        String to measure circumference	·        Ruler

Method:

1.      Prepare all the materials used in this experiment; in particular, bath bomb pieces can be placed on paper towel. The pieces must be of equal weight (ours was 5 g partly crushed); weigh it for accuracy.

2.      Add the pieces into the flask first; we used a funnel somewhat unsuccessfully (pieces were too big). If the acids are in the flask first, more gas may escape as the time taken to insert the pieces of bath bomb is a lot longer.

3.      Practice placing the neck of the balloon over the neck of the flask. *Very Important*

4.      Measure 25 mL of Hydrochloric Acid and pour into the conical flask when ready. Immediately pull on the balloon over the opening. Wait for 1 minute, and then measure the circumference of the balloon.

5.      Do the same for vinegar and lemon juice.

6.      After completing the one minute reactions for the three different acids in different flasks, ensure all observations and measurements have been undertaken and recorded.

Bath Bomb Size	Vinegar (Acetic acid) 4%	Hydrochloric Acid 1M	Lemon Juice (Citric acid) Standard Concentration
Partly Crushed	22 cm	24 cm	23 cm

Results

Despite the Hydrochloric Acid reaction happening so fast and therefore allowing quite some amount of CO₂ to escape before the balloon was placed onto the flask, the balloon circumference was still the largest of the three.

There were many factors affecting rate of reaction, including the size of the reactants (surface area)and the temperature of the reaction.

Discussion

The results were more or less what we expected. The Hydrochloric acid did blow up the largest balloon, however, the lemon juice, perhaps due to our better skills in covering the opening of the flask, was the second largest.

We deliberately changed the acid type which dissolves the bath bomb. We used citric acid, hydrochloric acid, and acetic acid. Our experiment was carried out at roughly about room temperature. There was no need to use a water bath as the temperatures of the solutions were above 20 °C. We used partially crushed bath bomb pieces because the weights of the crushed pieces were difficult to control. The size and weight of the large pieces were also difficult to control. We measured the circumference of the blown up balloons. The variable we deliberately changed was the direct cause of the change in size of the balloons.

There were many errors in our experiment. We could not control all of the variables apart from the acid type. Some systematic errors include the acid concentration of hydrochloric acid and vinegar. We assume that they are the same as the label indicates. The weight scales may have been faulty, especially if we took our bath bomb pieces separately. The balloon we used was stretched before the three experiments, but still will have slight unavoidable differences in size that render it incomparable. Random errors included our pouring, which did cause some spillage. Some pieces did not fit into the flask and the string to measure the balloon yielded measurements close to an approximation. At least a few centimetres was the ‘margin of error’.

Improvements I could make include better preparation in all areas. I would definitely be better at pouring without any spillage, and placing the balloon would be much quicker with teamwork. Weighing the bath bomb pieces could take a little longer time to ensure accuracy; the three piles could be weighed at once.

Common home-made bath bombs are said to be made with sodium bicarbonate and citric acid. These two ingredients react in an acid-base reaction style when they come in contact with water. The two are both weak acids and bases. Fillers can include corn starch. The filler indirectly controls the rate of reaction.

More H⁺ protons are released with hydrochloric acid than acetic acid, lemon juice, or water. This is because it is a strong acid, with an aggressive nature of releasing more of them.

Conclusion:

Hydrochloric acid can cause the bath bomb pieces to react and dissolve quicker than lemon juice or vinegar (weak acid) due to it being a strong acid. Further investigation will include researching what type the bath bomb was and experimenting with different bath bombs.

Noah Nishihara Home Group T09