Investigating Stoichiometry with Sodium Salts of Carbonic Acid Introduction:
The student will perform the experiment in order to find the percent yield by using the theoretical value found using the balanced equation for sodium carbonate as well as sodium bicarbonate. The objective is to stabilize the substances by titrations and finding the percent yield when all the data is collected. The purpose of this procedure is so that the student will get better understanding of stoichiometry. The student will also be reacting sodium bicarbonate and sodium carbonate with hydrochloric acid to produce sodium chloride, water and carbon dioxide. Experimental Procedure:
First the student will take the weight of a clean dry beaker and record the data. Next ass .15g of the first unknown substance. From there, the student will add 50ml of water to the beaker then dissolve the .15g of the first unknown substance into the water. Once the substance has dissolved, the student will add 10 drops of bromocresol (indicator) into the beaker. After the student will fill the buret all the way up with HCl. Once that is done, begin titration. The HCl should be added into the beaker until the indicator turns green. After it turns green the student will then place it on a hot plate and heat it till the CO2 evaporates and it turns blue again. After that let it cool. Once the substance is cooled. The student will then titrate once more till it turns yellow. The yellow color indicates that the substance has stabilized. Once the substance is fully titrated, the student will place the beaker back on to the hot plate and let all of the water evaporate out of the beaker till there is only the salt (unknown substance) left. Lastly, the student will then measure the weight of the beaker with the salt in it and record the data. Once the data has been obtained the student will subtract the weight of the beaker from the weight of the salt. That calculation will then be used to find the...
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