<span>Percentage
by mass is the amount in mass of a component in a mixture per 100 unit of mass of the
total mixture. Percentage by mass is the same as %w/w. We can determine this by dividing the mass of the solute with the total mass of the mixture. However, from the problem statement, we are given the volume of the water so there is a need to convert this value to mass by using the density of water. We calculate as follows:
Mass of solution = 100 mL (0.99993 g/mL) water + 25 g EtOH
Mass of solution = 124.993 g solution
%w/w = 25 g / 124.993 g x100
%w/w = 20% of EtOH</span>
I believe the correct answer from the choices listed above is the first option. There are about 840 candies present on all vans present. We calculate it by multiplying the number of total passengers by the number of candies each passenger is carrying. Hope this answers the question.
Explanation:
From the source, The student recrystallized biphenyl by using benzene. Biphenyl is non polar and so is benzene. Biphenyl is very soluble in benzene at low as well as high temperature. Thus, it do not recrystallize as like dissolves like and gives a very poor yield.
The good recovery of the product is dependent on compound having high solubility at the high temperatures and having low solubility at the low temperatures.
Amines are derivatives of
Ammonia (NH₃) in which atleast one hydrogen atom is replaced by an alkyl group. Amines are further classifies as;
Primary Amines: In primary amines the nitrogen atom is attached to two hydrogen atoms and one alkyl group.
Secondary Amines: In secondary amines the nitrogen atom is attached to two alkyl groups and one hydrogen atom.
Tertiary Amines: In tertiary amines the nitrogen atom is attached to three alkyl groups, hence it has no hydrogen atom.
Below are three isomers of tertiary amines with molecular formula
C₅H₁₃N.