محلول اور حیاتی سالمات

Written by Dr. Ayesha Nadeem (Chemistry)

ایم ڈی کیٹ · کیمیا · 8 سوالات

نام: ____________________ تاریخ: ____________

A solution has 2 moles of A and 3 moles of B. What is the mole fraction of A?
- A 2
- B 0.67
- C 0.4
- D 0.6
Osmotic pressure of a dilute solution is directly proportional to its:
- A Volume
- B Concentration
- C Density only
- D Colour
Dissolving a non-volatile solute in a solvent causes the vapour pressure of the solvent to:
- A Decrease
- B Increase
- C Become zero
- D Stay the same
What mass of NaCl is in 500 mL of a 0.1 M solution? (Na = 23, Cl = 35.5)
- A 0.585 g
- B 29.25 g
- C 2.925 g
- D 5.85 g
Glucose is classified as:
- A A polysaccharide
- B An aldohexose
- C A ketohexose
- D A disaccharide
What colour does starch give with iodine solution?
- A Red
- B Yellow
- C Blue-black
- D Green
Fats are esters of fatty acids with:
- A Glycerol
- B Glucose
- C Ethanol
- D Glycine
An amino acid exists mainly as a dipolar ion in water. This ion is called a:
- A Zwitterion
- B Free radical
- C Carbanion
- D Carbocation

جوابی کلید

1. C, 2. B, 3. A, 4. C, 5. B, 6. C, 7. A, 8. A

Mole fraction of A = 2 / (2 + 3) = 0.4.
Osmotic pressure = cRT, so it increases with the concentration of solute.
According to Raoult's law, the vapour pressure is lowered in proportion to the mole fraction of the solute.
Moles = 0.1 x 0.5 = 0.05 mol. Mass = 0.05 x 58.5 = 2.925 g.
Glucose has six carbons and an aldehyde group, so it is an aldohexose.
Iodine forms a blue-black complex with starch.
A fat, or triglyceride, is formed from one glycerol molecule and three fatty acids.
A zwitterion has both a positive NH3+ group and a negative COO- group in the same molecule.