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प्रश्न
The best way to recover sugar from an aqueous sugar solution is :
पर्याय
evaporation to dryness
distillation
filtration
crystallisation
उत्तर
crystallisation
Crystallisation is a better technique to recover sugar from sugar solution because sugar decomposes or gets charred on heating. Also, the soluble impurities get removed by crystallisation.
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संबंधित प्रश्न
Intermolecular force of attraction is maximum in ............ less in .......... and the least in .............
A kind of matter which can sublime is
Describe in your own words, what happens to the particles when salt dissolves in water.
Name one element, one compound and one mixture.
Which of the following substances are elements ?
Water, Salt, Mercury, Iron, Marble, Diamond, Wood, Nitrogen, Air, Graphite, Hydrogen, Oxygen, Sugar, Chlorine
Name two solid, two liquid and two gaseous elements at the room temperature.
“Is malleable and ductile” best describes :
Which of the following does not have a fixed melting point/boiling point ?
There are three substances X, Y and Z. The substance X does not have a fixed melting point or boiling point and it still shows the individual properties of its constituents. The substance Y is a pure substance which occurs in nature as such. The substance Y has a fixed melting point and boiling point but it cannot be broken down into simpler substances by any chemical means. The substance Z is also a pure substance whose properties are entirely different from those of its constituents. The substance Z can, however, be divided by electrolysis into two substances which belong to the same class of substances as Y.
- What type of substance could X be ? Name one substance like X.
- What type of substance could Y be ? Name one substance like Y.
- What type of substance could Z be ? Name one substance like Z.
- Which process involves absorption or release of an appreciable amount of energy : formation of substance X or formation of substance Z ?
- Name the three groups into which all the substances like Y are divided on the basis of their properties.
A, B and C are all liquids. Liquid A has a comparatively low boiling point. On heating, liquid A vaporises completely without leaving behind any residue. Liquid A is being used increasingly as a fuel in motor vehicles either alone or by mixing with petrol. Liquid B has a very high boiling point. It also vaporises completely on heating, without leaving any residue. Liquid B is a conductor of electricity and used in making thermometers. Liquid C has a moderate boiling point. On heating, liquid C vaporises leaving behind a white solid D which is used in cooking vegetables. The condensation of vapours from C give a liquid E which turns anhydrous CuSO4 to blue.
(a) Which liquid could be an element ? Name this element.
(b) Which liquid could be a mixture ? Name this mixture.
(c) Which liquid could be a compound ? Name this compound.
(d) What could the solid D be ?
(e) What do you think is liquid E ?
How much water should be mixed with 12 mL of alcohol so as to obtain 12 % alcohol solution ?
Define the Emulsion Give one example.
What is a colloid ? Give two examples of colloids (or colloidal solutions)
Which one of the following is not a chemical change ?
How will you separate a mixture containing sand and sugar ?
How is water purified on a large scale at water works ? Explain with the help of a labelled diagram. Name the substance which is added to kill germs in the drinking water supply ?
A solid mixture contains four constituents P, Q, R and S. P consists of tiny grains and it is mixed with
cement for plastering the walls. Q is a white solid which is recovered on a large scale from sea water by the
process of evaporation. R is in the form of tiny particles of a material whose corrosion is called rusting. And
S is a white solid which is used in making ordinary dry cells.
- What could P, Q, R and S be ?
- How would you separate a mixture containing P, Q, R and S ?
Name one pair of liquids which can be separated by using a separating funnel.
Justify your answer.
| Figure 1 | Figure 2 | Figure 3 |
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The arrangement of particles in three different phases of matter is shown above.
- Which state is represented by Fig. 1?
- In which state will the inter-particle attraction be maximum?
- Which one of them cannot be contained in an open vessel?
- Which one can take the shape of its container?
