What mass of sodium fluoride (used in water fluoridation and the manufacture of insecticides) is required to form 485 g of sulfur tetrafluoride? 3SCl2(l) + 4NaF(s) → SF4(g) + S2Cl2(l) + 4NaCl(s)

Acalorimeter is to be calibrated: 51.203 g of water at 55.2 degree c is added to a calorimeter containing 49.783 g of water at 23.5c. after stirring and waiting for the system to equilibrate, the final temperature reached is 37.6 degree c. specific heat capacity of water (s = 4.18 j/g∙degree c). calculate the calorimeter constant. (smδt)warm water = -[(smδt)cold water + (calorimeterδtcold water)]