Advertisements
Advertisements
प्रश्न
A child wanted to separate the mixture of dyes constituting a sample of ink. He marked a line by the ink on the filter paper and placed the filter paper in a glass containing water as shown in Fig.2.3. The filter paper was removed when the water moved near the top of the filter paper.
(i) What would you expect to see, if the ink contains three different coloured components?
(ii) Name the technique used by the child.
(iii) Suggest one more application of this technique.

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

(ii) The technique is called chromatography.
(iii) Separation of pigments present in chlorophyll.
APPEARS IN
संबंधित प्रश्न
A sample of drinking water was found to be severely contaminated with chloroform, CHCl3, supposed to be carcinogenic in nature. The level of contamination was 15 ppm (by mass).
- Express this in percent by mass.
- Determine the molality of chloroform in the water sample.
Dinitrogen and dihydrogen react with each other to produce ammonia according to the following chemical equation:
\[\ce{N2 (g) + 3H2 (g) → 2NH3 (g)}\]
(i) Calculate the mass of ammonia produced if 2.00 × 103 g dinitrogen reacts with 1.00 × 103 g of dihydrogen.
(ii) Will any of the two reactants remain unreacted?
(iii) If yes, which one and what would be its mass?
Solve the following problem:
Write the following number in ordinary decimal form:
3.49 × 10−11
Solve the following problem:
Write the following number in ordinary decimal form:
3.75 × 10−1
Solve the following problem:
Write the following number in ordinary decimal form:
5.00858585
Solve the following problem:
Perform the following calculation. Round off your answer to three digits.
`(8.94xx10^6)/(4.35xx10^4)`
Solve the following problem:
Your laboratory partner was given the task of measuring the length of a box (approx 5 in) as accurately as possible, using a metre stick graduated in milimeters. He supplied you with the following measurements:
12.65 cm, 12.6 cm, 12.65 cm, 12.655 cm, 126.55 mm, 12 cm.
Give your reason for rejecting each of the others.
Calculate the mass of sodium sulphate required to prepare its 20% (mass percent) solution in 100g of water?
Sulphuric acid reacts with sodium hydroxide as follows:
\[\ce{H2SO4 + 2NaOH -> Na2SO4 + 2H2O}\]
When 1 L of 0.1 M sulphuric acid solution is allowed to react with 1 L of 0.1 M sodium hydroxide solution, the amount of sodium sulphate formed and its molarity in the solution obtained is:
(i) 0.1 mol L–1
(ii) 7.10 g
(iii) 0.025 mol L–1
(iv) 3.55 g
Which of the following solutions have the same concentration?
(i) \[\ce{20 g of NaOH in 200 mL of solution}\]
(ii) \[\ce{0.5 mol of KCl in 200 mL of solution}\]
(iii) \[\ce{40 g of NaOH in 100 mL of solution}\]
(iv) \[\ce{20 g of KOH in 200 mL of solution}\]
