you follow the instructions, the POW kits will always heat the water above the correct temperature for pasteurization (65°C), but some people didn’t follow the instructions.

Those are different gas lawshere is a brief description of themcharles's law states that volume and temperature are directly proportional to each other as long as pressure is held constant.  boyle's law asserts that pressure and volume are inversely proportional to each other at fixed temperature.gay-lussac's law introduces a direct proportionality between temperature and pressure as long as it is at a constant volume.    source:

  the volume of  0.220 m k2s    solution  required  to  completely  react with 175 ml  of 0.115m co(no3)2  calculate the moles  of co(no3)2 =  molarity x volume/1000175 x0.115/1000= 0.02  moleswrite  the reacting  equationk2s(aq)  +  co(no3)2  = 2 kno3(aq)  + cos(s)by  use  of mole ratio between k2s to co(no3)2 which  is  1: 1 the moles of k2s is therefore = 175  x0.115/1000= 0.02  molesvolume = moles/molarity=0.02/0.22=0.09  ml  of k2s