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
Answer:
1. The enthalpy change for the backward reaction is –20 KJmol¯¹
2. The forward reaction is endothermic.
3. The activation energy for the forward reaction is +70 KJmol¯¹.
Explanation:
Considering the diagram given above, the following data were obtained:
1. The enthalpy change for the forward reaction being is +20 KJmol¯¹ and so, the enthalpy change for the backward reaction is –20 KJmol¯¹
2. The heat energy of the product is higher than that of the reactant. Therefore, the forward reaction is endothermic.
3. Activation energy is the minimum energy needed to be overcome in order for the reaction to proceed to product. It can be obtained from the energy profile diagram by considering the energy between the reactants and the peak.
For the question given above, Activation energy = 20 + 50
Activation energy = +70 KJmol¯¹
Answer:
at the top of the swing
at the top of the swing
at the bottom of the swing
at the bottom of the swing
Explanation:
A valid lewis structure of SO2 cannot be drawn without violating the octet rule.
correct me if i’m wrong.
A. The number of valence electrons increases as atomic mass increases. == Generally true for the representative elements since atomic mass generally increases with increasing Z.
B. The reactivity of alkali metals increases as atomic mass increases. == True. Atomic mass increases down the column and so does reactivity
C. The reactivity of the halogens increases as atomic mass increases. == False. Reactivity decreases down the column.
D. The number of valence electrons decreases across a period. == False. In general, the number of valence electrons increases across a period, particularly for the representative elements.
