After a reaction went to completion, the crude reaction mixture consisted of two compounds, A and B, which were isolated by extraction. After each compound was dried, their masses were found to be, 117 mg of compound A and 89 mg of compound B. Both compounds were individually recrystallized and weighed again. After recrystallization, the mass of compound A was 91 mg and the mass of compound B was 79 mg. Calculate the percent recovery from recrystallization for both compounds.

Percent recovery of A = 77.78%

Percent recovery of B = 88.8 %

Explanation:

Mass of impure compound A = 117 mg

Mass of impure compound B = 89 mg

Mass of A recovered = 91 mg

Mass of B recovered = 79 mg

Percent recovery of A = 91 mg/117 mg * 100

Percent recovery of A = 77.78%

Percent recovery of B = 79 mg/89 mg * 100

Percent recovery of B = 88.8 %

what is the volume occupied by 40 grams of argon gas (ar) at standard conditions? what volume, in liters, is occupied by 1.5 x 1023 

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.