2. Calculate the percent composition (percent by mass of each element) of NH_Br. 3. What physical property of water and HCl allows us to separate them from the zinc-chlorine compound produced in the reaction? 4. Imagine that during the experiment, a group allows their sample to get too hot so that some sample of the zinc-chlorine compound spatters out of the dish. When they calculate the percent by mass of zinc in the compound, will the calculated percent be higher or lower. Explain