I have a chemistry question that I am needing help on please?​

How many grams of mgbr2 are needed to produce 75g or metal?

Liquid from a brewery fermentation contains 10% ethanol and 90% water. part of the fermentation product (50,000 kg/h) is pumped to a distillation column on the factory site. under current operating conditions, a distillate of 45% ethanol and 55% water is produced from the top of the column at a rate of one-tenth that of the feed. what is the composition of the waste "bottoms" from the still?

Calculate the ph of a .10m nh4cl solution. the kb value for nh3 is 1.8×10^-5