Sncl2 is solid while sncl4 is liquid

As the oxidation state of a metal increases, its electronegativity increases and the bonds become increasingly covalent. SnCl2 forms a network solid where the atoms are bonded to one another throughout a network of polar covalent bonds. SnCl4 is molecular, and held together by weaker intermolecular forces called London dispersion forces. 

Enzyme make a hormone as a catalyst

Yes, endothermic means it turns cold. and some chemical changes include change of tempature.