Justify the following statements :
(i) Evaporation causes cooling(ii) Sponge though compressible yet is a solid(iii) The rate of diffusion of liquids is higher than that of solids.
Justify the following statements :
(i) Evaporation causes cooling(ii) Sponge though compressible yet is a solid(iii) The rate of diffusion of liquids is higher than that of solids.1) In evaporation a substance changes its state from liquid to gas, for this process to occur energy in the form of heat is required (endothermic process) which has to be taken from some source (surroundings). So the source, which loses heat apparently becomes 'cooler'. Hence it can be said that evaporation causes cooling.
2) The compressible nature of the sponge is due to its porous nature, air gets filled in the pores, when squeezed air is pushed out. When the applied force from sponge is withdrawn it resumes its original shape and therefore sponge is a solid.
3) The diffusion rate depends on the intermolecular space which is highest in gases (maximum diffusion rate) ,then liquids (moderate) and then solids (very less or no diffusion)
1) In evaporation a substance changes its state from liquid to gas, for this process to occur energy in the form of heat is required (endothermic process) which has to be taken from some source (surroundings). So the source, which loses heat apparently becomes 'cooler'. Hence it can be said that evaporation causes cooling.
2) The compressible nature of the sponge is due to its porous nature, air gets filled in the pores, when squeezed air is pushed out. When the applied force from sponge is withdrawn it resumes its original shape and therefore sponge is a solid.
3) The diffusion rate depends on the intermolecular space which is highest in gases (maximum diffusion rate) ,then liquids (moderate) and then solids (very less or no diffusion)
