Question

What will be the temparature of the mixture of 1 gram of ice at 0 degree celsius 1 gram of steam at 100 degree celcius.

Answer 1

Temperature always flow from hot to cold. So when 1 gram of ice at 0 degrees celcius and 1 gram of steam at 100 degrees celcius are mixed there will be a drop in temperature of steam and there will be a rise in temperature of ice.
Let the final temperature of the mixture be "T".
we take it to be closed system thus according to the energy conservation principle,

Heat gained = Heat lost
(100 - T) x 1 = (T -0) x 1
or
100 - T= T
100 = 2T
Hence T = 50 degrees celcius

Thus in a closed system there will be a flow of temperature from steam to ice till an equillibrium temperature of 50 degrees celcius is reached.