Answer:
A. 2.44g
B. Kd = 3.2
Explanation:
Concentration of benzoic acid = 50mL = 0.05L
Molecular weight = 122 g/mol
Moles of benzoic acid before the extraction = mass/molecular weight of Benzoic acid
= molar concentration * volume
Moles of benzoic acid before the extraction = 0.05 * 0.4
= 0.02moles of benzoic acid before extraction.
Mass of benzoic acid = 0.02 * 122
= 2.44 g
Partition coefficient, Kd is defined as the ratio of concentration of a substance in an organic medium to the concentration of the substance in the aqueous medium.
Since 1.22g of Benzoic acid was in Dicholoroethane, therefore (2.44 - 1.22)g of benzoic acid was in water.
Mass concentration of benzoic acid in water = mass of benzoic in water/volume of water
= 1.22/0.05
= 24.4 g/L
Mass concentration of benzoic acid in Dicholoroethane = mass of benzoic in Dicholoroethane/volume of Dicholoroethane
= 1.22/0.03
= 40.67g/L
Kd = [concentration]organic/[concentration]aqueous
= 40.66/24.4
= 1.67
We calculate first the number of moles of CO2 and H2O produced by dividing the given masses by the molar masses of CO2 and H2O.
moles CO2 = (12.9 g CO2) x (1 mole CO2 / 12 g CO2) = 1.075 moles.
moles H2O = (6.15 g H2O) x (1 mole H2O / 18 g H2O) = 0.36 moles
Then, we count the number of C, H, and O moles. This gives us 1.075 moles C, 2.5 moles O and 0.72 moles H. The empirical formula is,
C1.075H0.72O2.5
Simplifying,
C4H3O10
atoms definitions and I hope this helps