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WATER BATH
Water baths are special water troughs heated by electric coils below. They provide working temperatures above the normal room temperatures .it is constructed in such a way as to prevent heat loss by conduction or convection i.e. they are made of double metals, plastic or wood lagged with a poor conductor in between.
There are two types of water baths i.e.
(i) Thermostatic water bath which can measure and maintain temperatures correct to 0.1oc, they use toluene , mercury or capsules to control temperatures
(ii) The ordinary water bath, which can measure and maintain temperatures correct to 1oc, they use bimetallic strips to control their temperatures
Steam Baths
Steam baths are used for heating flammable liquids. Steam baths provides temperature up to 100 oc . It involves evaporation by moist heat, the contents retains moisture after evaporation
Its water level should be kept constant by adding more water by use of constant head device which have constant pressure
Oil Baths
Oil baths are used for temperatures above 100oc. they are generally heated by a gas burner . They are used as in water bath but for reaction mixtures which have been held for a time at a temperature in excess of 100 oc
Sand Bath
Sand baths are shallow trays of metals containing thin layer of sand , the sand layer should not be very thick because sand is a bad conductor of heat hence too much heat will be needed to warm it
Sand baths provides uniform heating hence help to avoid cracking or fracture of glasswares . Temperature measures and controls are unnecessary for sand baths
Hot plates are used to provide moderate heating in the laboratory especially .for long periods of heating. They are not very efficient since they lose a lot of heat.
They have thermostats to regulate their heating temperatures.
THE BUNSEN AND MEKER BURNERS
They are used for direct heating in quantitative testing and are sometimes used for distillation but not with the inflammables. Bunsen burner has one hole and burns with single flame while Meker burner have many small holes which burn with many small flames