Ms. block's students are studying chemical reactions as well as the law of conservation of matter. a classic reaction occurs when a metal is added to hydrochloric acid. miguel and kai are about to add 30g of hydrochloric acid (hcl) to 30g of magnesium (mg) in a large test tube. how could you adapt the boys experimental design so they would definitely be testing the law of conservation of matter? a) the boys could use less hydrochloric acid to produce less gas bubbles. b) the boys should use a container, such as a flask, that is larger than a test tube. c) the boys could cover the end of the test tube with a balloon to capture the escaping gas. d) one of the boys could place a hand over the end of the test tube to create a closed system.