Advertisements
Advertisements
Why does table salt, NaCl, sometimes appear yellow in colour?
Concept: undefined >> undefined
Why does white ZnO (s) becomes yellow upon heating?
Concept: undefined >> undefined
Advertisements
Match the types of defect given in Column I with the statement given in Column II.
| Column I | Column II |
| (i) Impurity defect | (a) NaCl with anionic sites called F-centres |
| (ii) Metal excess defect | (b) FeO with Fe3+ |
| (iii) Metal deficiency defect | (c) NaCl with Sr2+ and some cationic sites vacant |
Concept: undefined >> undefined
A sample of ferrous oxide has actual formula Fe0.93O1.00. In this sample what fraction of metal ions are Fe2+ ions? What type of nonstoichiometric defect is present in this sample?
Concept: undefined >> undefined
At a given temperature, osmotic pressure of a concentrated solution of a substance ______.
Concept: undefined >> undefined
Which of the following statements is false?
Concept: undefined >> undefined
Isotonic solutions must have the same:
(i) solute
(ii) density
(iii) elevation in boiling point
(iv) depression in freezing point
Concept: undefined >> undefined
In isotonic solutions:
(i) Solute and solvent both are same.
(ii) Osmotic pressure is same.
(iii) Solute and solvent may or may not be same.
(iv) Solute is always same solvent may be different.
Concept: undefined >> undefined
Give an example of a material used for making semipermeable membrane for carrying out reverse osmosis.
Concept: undefined >> undefined
Match the items given in Column I and Column II.
| Column I | Column II |
| (i) Saturated solution | (a) Solution having same osmotic pressure at a given temperature as that of given solution. |
| (ii) Binary solution | (b) A solution whose osmotic pressure is less than that of another. |
| (iii) Isotonic solution | (c) Solution with two components. |
| (iv) Hypotonic solution | (d) A solution which contains maximum amount of solute that can be dissolved in a given amount of solvent at a given temperature. |
| (v) Solid solution | (e) A solution whose osmotic pressure is more than that of another. |
| (vi) Hypertonic solution | (f) A solution in solid phase. |
Concept: undefined >> undefined
Discuss biological and industrial importance of osmosis.
Concept: undefined >> undefined
How can you remove the hard calcium carbonate layer of the egg without damaging its semiprermiable membrane? Can this egg be inserted into a bottle with a narrow neck without distorting its shape? Explain the process involved.
Concept: undefined >> undefined
At high concentration of soap in water, soap behaves as ______.
Concept: undefined >> undefined
Which of the following options are correct?
(i) Micelle formation by soap in aqueous solution is possible at all temperatures.
(ii) Micelle formation by soap in aqueous solution occurs above a particular concentration.
(iii) On dilution of soap solution micelles may revert to individual ions.
(iv) Soap solution behaves as a normal strong electrolyte at all concentrations.
Concept: undefined >> undefined
Method of formation of solution is given in Column I. Match it with the type of solution given in Column II.
| Column I | Column II |
| (i) Sulphur vapours passed through cold water | (a) Normal electrolyte solution |
| (ii) Soap mixed with water above critical micelle concentration | (b) Molecular colloids |
| (iii) White of egg whipped with water | (c) Associated colloid |
| (iv) Soap mixed with water below critical micelle concentration | (d) Macro molecular colloids |
Concept: undefined >> undefined
Which of the following oxidation state is common for all lanthanoids?
Concept: undefined >> undefined
There are 14 elements in actinoid series. Which of the following elements does not belong to this series?
Concept: undefined >> undefined
Which of the following actinoids show oxidation states upto +7?
(i) Am
(ii) Pu
(iii) U
(iv) Np
Concept: undefined >> undefined
Assertion: Actinoids form relatively less stable complexes as compared to lanthanoids.
Reason: Actinoids can utilise their 5f orbitals along with 6d orbitals in bonding but lanthanoids do not use their 4f orbital for bonding.
Concept: undefined >> undefined
Complete the following reaction sequence.
\[\begin{array}{cc}
\ce{O}\phantom{...............................................}\\
||\phantom{...............................................}\\
\ce{CH3 - C - CH3 ->[(i) CH3MgBr][H2O] (A) ->[Na metal][Ether] (B) ->[CH3 - Br] (C)}
\end{array}\]
Concept: undefined >> undefined
