How many kilocalories are required to heat 100.00 g of water from 34.2°c to 96.5°c?

Heat required in calories is given by product of mass in g and change in temperature in degree Celsius.

Formula is given by:

where, Q = heat required in calories

m = mass of substance in g

= change in temperature in degree Celsius

Insert the given vales of mass of water and temperature in above formula, we get:

 =

=

Now,

=

Thus, heat in kilocalories  =

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation: