Lab STOI 0386-Chemistry (Pre Lab) Flashcards

3. A student used the procedure in this experiment to determine the empirical formula of aluminum chloride. In the student's experiment, a sample of aluminum (Al), weighing 1.500 g, reacted completely with an excess of aqueous HCl to produce 7.431 g of aluminum chloride.

(1) Determine the percent Al in the aluminum chloride formed during the reaction

20.2% Al

3. A student used the procedure in this experiment to determine the empirical formula of aluminum chloride. In the student's experiment, a sample of aluminum (Al), weighing 1.500 g, reacted completely with an excess of aqueous HCl to produce 7.431 g of aluminum chloride.

(2) Determine the percent Cl in the aluminum chloride formed during the reaction

79.8% Cl

3. A student used the procedure in this experiment to determine the empirical formula of aluminum chloride. In the student's experiment, a sample of aluminum (Al), weighing 1.500 g, reacted completely with an excess of aqueous HCl to produce 7.431 g of aluminum chloride.

(3) Complete Table 3 by calculating the formula masses of a variety of compounds of the type Al x Cl y using small values for x and y. The molar mass of Al is 26.98 g/mol; that of Cl is 35.45 g/mol. Then calculate the percent Al and percent Cl in each of these compounds.

Compound Formula Mass %Al %Cl
AlCl ____________g/mol _________% ________%
AlCl2 ____________g/mol _________% ________%
AlCl3 ____________g/mol _________% ________%
Al2Cl3 ____________g/mol _________% ________%
Al3Cl2 ____________g/mol _________% ________%

Compound Formula Mass %Al %Cl
AlCl 62.43 g/mol 43.22% 56.78%
AlCl2 97.89 g/mol 27.56% 72.43%
AlCl3 133.34 g/mol 20.2% 79.8%
Al2Cl3 160.32 g/mol 33.66% 66.34%
Al3Cl2 151.85 g/mol 53.30% 46.69%

3. A student used the procedure in this experiment to determine the empirical formula of aluminum chloride. In the student's experiment, a sample of aluminum (Al), weighing 1.500 g, reacted completely with an excess of aqueous HCl to produce 7.431 g of aluminum chloride.

(4) Compare your results for 3.(1) and 3.(2) with the data in Table 3 to determine the empirical formula of aluminum chloride

AlCl3

Lab STOI 0386-Chemistry (Pre Lab)

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