EVAPORATION

Classify the following processes as exothermic or endothermic. (E) Rubbing alcohol evaporates

A child running a temperature of 101^F is given and antipyrin (i.e. a madicine that lowers fever) which cause an increase in the rate of evaporation of sweat from his body. If the fever is brought down to 98^@F in 20 min., what is the averatge rate of extra evaporation caused, by the drug ? Assume the evaporation mechanism to the only way by which heat is lost. The mass of the child is 30 kg. The specific heat of human body is approximately the same as that of water and latent heat of evaporation of water at that temperature is about 580 cal. g^(-1).

Assertion : van Arkel method is used for refining of Zinc. Reason : In this method impure is evaporated to obtain the pure metal as distillate .

When a sulphur sol is evaporated, solid sulphur is left. On mixing with water no colloidal sol is formed. The sulphur sol is :

If an average jogs, he produces 14.5xx10^(3) cal/min. This is removed by the evaporation of sweat. The amount of sweat evaporated per minute (assuming 1 kg requires 580xx10^(3) cal for evaporation) is a) 0.25 kg b) 2.25 kg c) 0.05 kg d) 0.20 kg

A swimmer coming out from a pool is covered with a film of water weighing about 80g . How much heat must be supplied to evaporate this water ? If latent heat of evaporation for H_(2)O is 40.79 kJ mol^(-1) at 100^(@)C .

A swimmer coming out from a pool is covered with a film of water weighing about 80g . How much heat must be supplied to evaporate this water ? If latent heat of evaporation for H_(2)O is 40.79 kJ mol^(-1) at 100^(@)C .

The evaporating dish is made of

What type of bonds are broken when water evaporates?

The liquid which evaporates and then condenses during the process of distillations……………