If hot water is mixed with cold water

Why hot water is preferred to cold water for washing clothes?

10 litres of hot water at 70^@C is mixed with an equal volume of cold water at 20^@ C . Find the resultant temperature of the water. (Specific heat of water = 4200 J//kg -K ).

Large fresh water reservoir is fitted with two types of feeder pipes- hot water pipes and cold water pipes. Six cold water pipes alone can fill the reservoir in 12 hours. 3 cold water pipes and 9 hot water pipes together can fill the reservoir in 8 hours. How long will 5 hot water pipes alone take to fill the reservoir? 18 h r s 36 m in b. 20 h r s 45 m in c. 21 h r s 36 m in d. none of these

Give the names of the following : (i) A metal which reacts with cold water (ii) A metal which reacts with hot water (iii) A metal which reacts neither with cold water nor with hot water, but with steam

Metal chloride A is soluble in hot water but insoluble in cold water. Select correct statement about A. Thus

What can it be, if the precipitate of group I is soluble in hot water and insoluble in cold water?