Is mass conserved when 40 g of sodium hydroxide undergoes a chemical change during an interaction with 36.5 g of hydrogen chloride? Use complete sentences to support your answer by explaining how this can be demonstrated.

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?