Questions

∆Tf = kf.m 

for ethylene glycol in aq. solution

 $$\begin{gathered} ∆Tf = kf wmol.wt × 1000wt. of solvent \\ 6 = 1.86 x w x 100062 x 4000 \end{gathered}$$

=> w = 800 g

So, the weight of solute should be more than 800 g.

White phosphorus undergoes spontaneous combustion when exposed to air. In order to prevent this spontaneous ignition, it is preserved under water. 

All those activities which have been planned out by the marketing department must be tried out in the market several times in order to be able to conclude if such activities are worthwhile or not. Such activities may be repeated several times over a period say six months or a year in order to be able to decide whether to stick to them or replace them with other better alternatives. Monitoring and controlling the marketing activities entails keeping proper records of the various activities and tracking them time and again particularly when it comes to the media, when to promote the product, cost factor, reach or the number of persons towards whom the promotions have been targeted, responses generated, sales generation and return on sales

Chlorine is the most commonly used bleaching agent.

Bleaching agents are compounds which are used to remove color from substances such as textiles. A bleaching agent is a material that lightens or whitens a substrate through the chemical reaction. The bleaching reactions usually involve oxidative or reductive processes that degrade color systems.