2nd Midterm Chem Lag

Question 1

is an excellent procedure to use in the separation, purification and identification of components present in a very small amount of the mixture.

Answer 1

Chromatography

Question 2

Chromatography procedure to use in the ________ of components present in a very small amount of the mixture.

Answer 2

separation
purification
identification

Question 3

• Simplest and the most common type of chromatographic separation is
• Which make use of sheets of filter paper.

Answer 3

paper chromatography

Question 4

Acts as an inert carrier for the stationary liquid phase

Answer 4

filter paper

Question 5

Carried through the paper by capillary action

Answer 5

the second solvent (mobile phase)

Question 6

Differentially absorbed by the two solvents and moves at different rates through the column (filter paper) depending upon their partition coefficient between the solvent and the aqueous phase

Answer 6

substances

Question 7

This dependence maybe related to the ratio between the _________ developed by each component of the mixture from the origin and the distance of the solvent front from origin.

Answer 7

distance of the spot

Question 8

Is called the Rf value of the substance in a particular solvent.

Answer 8

ratio

Question 9

What are the Materials for chromatography

Answer 9

filter paper
fine capillary tubes
ethyl alcohol
test solution (black sign-pen ink)

Question 10

What are the Apparatus in chromatography?

Answer 10

graduated cylinder
pipette
2 wide mouthed jars with lid
(diameter of 10 cm and 15-20cm high)

Question 11

Is a process that is usually emploved for the purification of liquid organic substances. This involves the conversion of the liquid to the vapor state with the aid of heat and condensation of the vapors back to the liquid state.

Answer 11

Distillation

Question 12

The recondensed liquid is called the

Answer 12

distillate

Question 13

A single, individual organic substance is readily purified with the ordinary distillation apparatus which consist of distilling flask fitted with a

Answer 13

thermometer and water-cooled condenser.

Question 14

Are placed in the flask with the substance to be distilled; they prevent bumping by producing a constant stream of bubbles which keeps the liquid in motion.

Answer 14

2/3 pieces of broken porcelain chips

Question 15

If the substance is ________ the flask is heated by a water bath. As the boiling point of every pure organic substance is constant at a definite pressure, it is one of the most important criteria of purity.

Answer 15

quite volatile (low boiling) ,

Question 16

Materials use for distillation

Answer 16

acetone
water
5% sodium nitroprusside
5 % sodium hydroxide

Question 17

Apparatus use for distillation

Answer 17

distilling flask
thermometer
condenser
adapter
erlenmeyer flask
clamps
iron stand
burner
corks

Question 18

After placing two drops of distillate in a dry evaporating dish, it ignited.

Answer 18

Distillation A : Ignition Test

Question 19

After placing a drop of sodium nitroprusside and a drop of sodium hydroxide, it produced red color.

Answer 19

Distillation A : Sodium Nitroprusside Test

Question 20

did not ignite after placing an ignited matchstick in it.

Answer 20

Distillation B : Ignition Test

Question 21

There is no positive color reaction for the distillate B.

Answer 21

Distillate B