Advertisements
Advertisements
Method by which lyophobic sol can be protected?
Concept: undefined >> undefined
Which of the following colloids cannot be coagulated easily?
(i) Lyophobic colloids.
(ii) Irreversible colloids.
(iii) Reversible colloids.
(iv) Lyophilic colloids.
Concept: undefined >> undefined
Advertisements
What happens when gelatin is mixed with gold sol?
Concept: undefined >> undefined
Match the items given in Column I and Column II.
| Column I | Column II |
| (i) Protective colloid | (a) \[\ce{FeCl3 + NaOH}\] |
| (ii) Liquid-liquid colloid | (b) Lyophilic colloids |
| (iii) Positively charged colloid | (c) Emulsion |
| (iv) Negatively charged colloid | (d) \[\ce{FeCl3}\] + hot water |
Concept: undefined >> undefined
A number of elements are available in earth’s crust but most abundant elements are ______.
Concept: undefined >> undefined
Explain why ozone is thermodynamically less stable than oxygen.
Concept: undefined >> undefined
Coagulation of egg white on boiling is an example of denaturation of protein. Explain it in terms of structural changes.
Concept: undefined >> undefined
Read the passage carefully and answer the questions that follow:
| Henna is investigating the melting point of different salt solutions. She makes a salt solution using 10 mL of water with a known mass of NaCl salt. She puts the salt solution into a freezer and leaves it to freeze. She takes the frozen salt solution out of the freezer and measures the temperature when the frozen salt solution melts. She repeats each experiment. |
| S.No | Mass of the salt used in g |
Melting point in °C | |
| Readings Set 1 | Reading Set 2 | ||
| 1 | 0.3 | -1.9 | -1.9 |
| 2 | 0.4 | -2.5 | -2.6 |
| 3 | 0.5 | -3.0 | -5.5 |
| 4 | 0.6 | -3.8 | -3.8 |
| 5 | 0.8 | -5.1 | -5.0 |
| 6 | 1.0 | -6.4 | -6.3 |
Assuming the melting point of pure water as 0°C, answer the following questions:
- One temperature in the second set of results does not fit the pattern. Which temperature is that? Justify your answer.
- Why did Henna collect two sets of results?
- In place of NaCl, if Henna had used glucose, what would have been the melting point of the solution with 0.6 g glucose in it?
OR
What is the predicted melting point if 1.2 g of salt is added to 10 mL of water? Justify your answer.
Concept: undefined >> undefined
Differentiate between the following:
Lyophobic Sol and Lyophilic Sol
Concept: undefined >> undefined
Which of the following cell was used in the Apollo space programme?
Concept: undefined >> undefined
When 25.6 g of sulphur was dissolved in 1000 g of benzene, the freezing point lowered by 0.512 K. Calculate the formula of sulphur (Sr).
(Kf for benzene = 5.12 K kg mol−1, Atomic mass of sulphur = 32 g mol−1)
Concept: undefined >> undefined
Out of the following 1.0 M aqueous solution, which one will show the largest freezing point depression?
Concept: undefined >> undefined
What structural change will occur when a native protein is subjected to change in pH?
Concept: undefined >> undefined
Ibrahim collected 10 mL each of fresh water and ocean water. He observed that one sample labeled “P” froze at 0° C while the other “Q” at -1.3° C. Ibrahim forgot which of the two, “P” or “Q” was ocean water. Help him identify which container contains ocean water, giving rationalization for your answer.
Concept: undefined >> undefined
Determine the osmotic pressure of a solution prepared by dissolving 2.5 × 10−2 g of K2SO4 in 2L of water at 25°C, assuming that it is completely dissociated.
(R = 0.0821 L atm K−1 mol−1, Molar mass of K2SO4 = 174 g mol−1)
Concept: undefined >> undefined
Give the structures of A, B and C in the following reactions:
Concept: undefined >> undefined
Although phenoxide ion has more number of resonating structures than carboxylate ion, carboxylic acid is a stronger acid than phenol. Give two reasons.
Concept: undefined >> undefined
How would you account for the following:
The chemistry of actinoids is more complicated as compared to lanthanoids.
Concept: undefined >> undefined
Write the structures of main products when benzene diazonium chloride `(C_6H_5N_2^(+)Cl^-)`reacts with the following reagents:
CuCN/KCN
Concept: undefined >> undefined
Write the structures of main products when benzene diazonium chloride `(C_6H_5N_2^(+)Cl^-)`reacts with the following reagents:
H2O
Concept: undefined >> undefined
