Chemistry 4 Marks Questions

Read the following text carefully and answer the questions that follow:
The actinoids include the fourteen elements from Th to Lr. The actinoids are radioactive elements and the earlier members have relatively long half-lives, the latter ones have half-life values ranging from a day to 3 minutes for lawrencium. The latter members could be prepared only in nanogram quantities. Actinoids show a greater range of oxidation states. The elements, in the first half of the series frequently exhibit higher oxidation states. The actinoids resemble the lanthanoids in having more compounds in +3 state than in the +4 state. All the actinoids are believed to have the electronic configuration of 7s² and variable occupancy of the 5f and 6d subshells. The magnetic properties of the actinoids are more complex than those of the lanthanoids. The variation in the magnetic susceptibility of the actinoids with the number of unpaired 5f electrons is roughly parallel to the corresponding results for the lanthanoid.
i. Actinoid contraction is greater from element to element than lanthanoid contraction. Why?
ii. Actinoids show irregularities in their electronic configuration. Justify?
iii. The actinoid metals are all silvery in appearance but display a variety of structures than lanthanoid give reason.
OR
iii. The magnetic properties of the actinoids are more complex than those of the lanthanoids. Why?

Read the following text carefully and answer the questions that follow:
The boiling point elevation and the freezing point depression of solutions have a number of practical applications. Ethylene glycol (CH₂OH-CH₂OH) is used in automobile radiators as an antifreeze because it lowers the freezing point of the coolant. The same substance also helps to prevent the radiator coolant from boiling away by elevating the boiling point. Ethylene glycol has a low vapour pressure. We can also use glycerol as an antifreeze. In order for boiling point elevation to occur, the solute must be non-volatile, but no such restriction applies to freezing point depression. For example, methanol (CH₃OH), a fairly volatile liquid that boils only at 65°C is sometimes used as antifreeze in automobile radiators.
i. Out of the CH₃OH and C₆H₁₂O₆, which is a better reagent for depression in freezing point but not for elevation in boiling point?
ii. Will the depression in freezing point be same or different, if 0.1 moles of sugar or 0.1 moles of glucose is dissolved in 1 L of water?
iii. 124 g each of the two reagents glycerol and glycol are added in 5 kg water of the radiators in the two cars. Which one is better for a car? Justify your answer.
OR
iii. If the cost of glycerol, glycol and methanol are the same, then what would be the sequence of the economy to use these compounds as antifreeze?