According to the kinetic theory of gases, the collisions among the molecules are perfectly elastic, that is, when the collision of the molecules takes place, they bounce off each other with no gain or loss of energy. No repulsive or attractive forces take part at the time of collisions, so energy is conserved.
Molality is defined as the number of moles of solute in 1 kg of solvent.
molality of solution to be prepared is 0.50 molal
this means that in 1000 g of water there should be 0.50 mol of NaCl
if 1000 g of water should contain - 0.50 mol
then 750.0 g of water requires - 0.50 mol/kg x 0.750 kg = 0.375 mol
mass of NaCl in 0.375 mol - 58.5 g/mol x 0.375 mol = 21.9 g
therefore a mass of 21.9 g of NaCl is required
it will sink
Explanation:
the solid iron will sink because it is dense than the liquid iron I will sink and it will melt
Answer: 
Explanation:
Given
Mass of water in the sample is 
Temperature changes from 
to 
Change in temperature is 
We know, specific heat of water is 
Heat absorbed is given by
Thus, water absorbs of heat from hot plate.
