Solutions Flashcards
What happens when acetone is added to pure ethanol
When acetone is added to ethanol,some of H bond btw the ethanol molecules break down resulting in increase in vapor pressure of mixture.The mixture shows positive deviation from Raoults law
Measurement of osmotic pressure method is preferred for determination of molar mass of macromolecules such as protein and polymers?
as compared to other colligative properties,its magnitude is large even for very dilute solutions at room temperature.Macromolecules are generally not stable at higher temperatures and polymers have poor solubility
What are isotonic solutions
two solutions with same osmotic pressure at a given temperature
no osmosis btw these solutions
Some liquid on mixing form azeotropes .What are azeotropes
They are the binary mixture of solution that have same composition in liquid and vapor phase and have a sharp boiling point like pure liquids
Some liquid on mixing form azeotropes .What are azeotropes
They are the binary mixture of solution that have same composition in liquid and vapor phase and boil at constant temperature like pure liquids
why is air diluted with helium in the tank used by scuba divers?
To avoid bends as well as the toxic effects of high concentrations of Nitrogen in the blood.
Air is diluted with helium due to its lower solubility in blood than nitrogen
why is meat preserved for longer time by salting
Salt removes water from meat by osmosis.Since there is no water left in meat , microorganisms are unable to germinate.This helps to store meat for longer time.
Examples of positive and negative deviations from Raoults law
positive deviation:
ethanol + acetone
ethanol + water
methanol + water
negative deviation:
chloroform + acetone
HNO3+ H2O
HCl+ H2O
Define azeotropes .What type of azeotropes are formed by positive deviation from Raoults law??Give example
or
Define Azeotropes.What type of azeotropes are formed by negative deviation from Raoults law??give examples.
Azeotropes are binary mixture solutions that have the same composition in liquid and vapor phase and boil at constant temperature like pure liquids.
Minimum boiling azeotropes eg.Ethanol + Water
or
Maximum boiling point azeotropes.eg:nitric acid + water
Why are aquaric species more comfortable in cold water than in warm water
Solubility of oxygen decreases with increase in temperature.Hence aquatic species are more comfortable in cold water
What happens when we place the blood cell in water(hypotonic solution) give reason.
Due to osmosis, water molecules move in blood cell.As a result blood cell swell and may even burst
