During a science lab investigating chemical reactions, mrs. gray's students placed an antacid tablet in a zip lock bag. they recorded the mass of the tablet, 25 grams, and the bag, 60 grams. then they carefully added 50 grams of water and quickly sealed the bag. the tablet began to fizz and soon disappeared. the bag was filled with gas. if the mass of the liquid after the reaction is completed is still 50 grams, how much gas is produced?

25 g.

Justification:

The law of conservation of mass states that the mass is conserved during a chemical reaction.

The disappearance of the tablet along with the formation of bubbles (fizzing) are a clear indication that a chemical reaction happened.

Since all the provisions were taken to prevent the escape of the products of the reaction (gaseous, liquids or solids), you can use the law of mass conservation to calculate the mass of the gas produced:

Law of mass conservation: mass of the rectants = mass of the products.

You can state it as: mass before the reaction = mass after the reaction.

                        Before reaction           After reaction

tablet                  25 g                                0

bag                      60 g                               60 g

liquid                   50 g                               50 g

gas                          0                                     x

total                   135 g                             110g + x

Equation: