Crystallisation - class-VII
Description: crystallisation | |
Number of Questions: 25 | |
Created by: Gauri Chanda | |
Tags: changes around us element, compound and mixture chemistry physical and chemical changes |
What is a chemical change?
Which of the following cause a substance to change into an entirely new substance with a new chemical formula?
Which of the following is not a chemical change?
Insoluble impurities from solution during crystallization are removed by :
While forming crystals, it is important to :
Crystallisation is an example of chemical change.
The forbidden gap in germanium crystal is
Which of the following is not a feature of chemical change?
(I) Original substance can be obtained by simple physical methods.
(II) It is a temporary change.
(III) The new substances formed have properties different from those of the reacting substances.
Sun tanning is a/an :
Which factor when increased will cause an uncatalyzed reaction to proceed more quickly?
One of most common solvent used for crystallization is:
The process of obtaining salt by evaporation of seawater is known as :
Crystalisation takes place by the process of :
Crystals are formed by ions, atoms, and molecules having an internal pattern that is ___________ and ___________.
Which of the following is the most common solvent used for crystallization?
Solvent dissolve large amount of solute at________
Vacuum desiccator is used _____
Phenolphthalein is a synthetic indicator and its color in acidic and basic solutions, respectively are:
A synthetic indicator phenolphthalein gives ________ colour in basic solution.
Which of the following represents correct statement(s)?
Salt can be obtained by ___________ of sea water.
The process of forming large crystals of pure substances from their solutions is known as __________.
Crystallisation is an example of ____________.
A synthetic indicator phenolphthalein gives _____ colour in acidic solution.