question_answer 41)

                  During summers in India, one of the common practice to keep cool is to make ice balls of crushed ice, dip it in flavoured sugar syrup and sip it. For this a stick is inserted into crushed ice and is squeezed in the palm to make it into the ball. Equivalently in winter in those areas where it snows, people make snow balls and throw around. Explain the formation of ball out of crushed ice or snow in the light of P-T diagram of water.                

Answer:

                                  When pressure is increased in solid state (at \[{{0}^{o}}C,\] 1 atm) ice change into liquid state (water) while decreasing pressure in liquid state (at \[{{0}^{o}},\] 1 atm), water changes to ice. When we squeeze the crushed ice, some of it melts into water which fills the gaps between ice flakes. On the other hand, when pressure is released, this water freezes into ice and binds together all the ice flakes to make the ball more stable.