Science case /data -based [Che-4M]

(c) For the separation of those solutes that dissolve in the same solvent.

(d) To separate drugs from blood.

(b) The components of the ink will travel with water and we would see three bands on the filter paper at             various lengths.

(c) Chromatography.

1. When solid A is dissolved in water, chemical change takes place. This is because the properties of products B and C are entirely different from those of solid A and water.
2. Physical change occurs when solid D is dissolved in water. This is because product E shows the properties of both, solid D and water.
3. Sodium metal could behave like solid A.

• Product B is sodium hydroxide.
• Product C is hydrogen.

4. Solid D is ammonium chloride.
5. D can be recovered from E by evaporation.

1. Tincture iodine is a mixture of two materials X and Y. So, X is alcohol.
2. The material Y has a property and its solid form can be converted directly into vapours on heating by the process called Z. So, Y is iodine.
3. Process Z is called sublimation.
4. Process used to recover both the components, i.e., alcohol and iodine, from the tincture of iodine is distillation.
5. The process used to recover component Y only from the tincture of iodine is evaporation.

1. Mixtures like A are known as suspensions.
2. Mixtures like B are known as colloids.
3. Mixtures like C are known as true solutions.
4. The phenomenon exhibited by A and B, which occur on passing a beam of light through them, is called Tyndall effect.
5.  

• Mud water mixture is like A.
• Soap solution is a mixture like B.
• Sugar solution is a mixture like C.

1. Liquid A is organic and liquid B is inorganic. When mixed, they form a single layer, i.e., they are miscible liquids. So, we will use fractional distillation to separate the mixture of liquid A and liquid B.
2. Liquid B is inorganic and liquid C is organic. We will use a separating funnel to separate the mixture of liquid B and liquid C as they form two different layers.
3.  

1. Liquid A is organic. When liquid A and liquid B are put together in a container, they form a single layer. So, alcohol would behave like liquid A.
2. Liquid B is inorganic. So, water would behave like liquid B.
3. Liquid C is organic. When liquid B and liquid C are mixed together, they form two separate layers. Oil would behave like liquid C.

1. Y will be collected from the area near the bottom of the fractional distillation column because it has highest boiling point (-183°C).
2. Z will be collected from the top part of the fractional distillation column because it has lowest boiling point (-196°C).
3. X will be collected from the middle part of the fractional distillation column because it has a boiling point -186°C, which is lower than that of Y but higher than that of Z.
4. X is liquid argon, Y is liquid oxygen, and Z is liquid nitrogen.

1. Constituent A is yellow coloured solid element. It could be sulphur.
2. Sulphur dissolves in liquid D. So, liquid D could be carbon disulphide.

1. Constituent B is a blue coloured salt, which is insoluble in carbon disulphide but dissolves in water. So, it could be copper sulphate.
2. Liquid E could be water as it dissolves copper sulphate.

3. Liquid C could be vegetable oil as it turns into a solid fat on hydrogenation.
4. We will separate the mixture containing A, B, and C by following process:

• At first, we filter the mixture of A, B, and C.
• Vegetable oil C, being liquid, will be obtained as a filtrate.
• Residue consists of A(sulphur) and B(copper sulphate).
• We add water to the residue and shake it before filtering. A(sulphur) is obtained as residue.
• Now, we evaporate filtrate to obtain B(copper sulphate).

1. P consists of tiny grains and it is mixed with cement for plastering the walls. So, P is sand. Q is a white solid, which is recovered on a large scale from sea water by the process of evaporation. It is common salt. R is in the form of tiny particles of materials, whose corrosion is called rusting. It is, iron filings. S is ammonium chloride.
2. At first, let us take the mixture of P, Q, R, and S.

1. We first separate R(iron filings) by using a magnet to attract them. Then separate S(ammonium chloride) by sublimation.
2. Now, we shake P(sand) and Q(common salt) with water. The mixture is then filtered.
3. Sand is obtained as residue.
4. Now, we will evaporate the filtrate to dryness to obtain Q(common salt).

1. X type of solutions is known as unsaturated solution.
2. Y type of solutions is known as saturated solution.
3. If solution Y at 30°C is cooled down to 10°C by keeping the beaker in crushed ice, some of the dissolved parts of the solid will separate from the solution and will settle at the bottom of the beaker as crystals. This occurs because of the decrease in the solubility of solids and reduction in temperature.
4. Solubility refers to the amount of a solid dissolved in 100 grams of water.