PLEASE HELP ASAP 19. For the following antacid reaction, list the reactants:
2HCl + CaCO3 ---> CaCl2 + CO2 + H2O
a. HCl
b. HCl and CaCO3
c. CaCl2, CO2, and H2O
d. None of the above.

20. For the following antacid reaction, list the products:
2HCl + CaCO3 ---> CaCl2 + CO2 + H2O
a. HCl
b. HCl and CaCO3
c. CaCl2, CO2, and H2O
d. None of the above.

In 1901, thomas edison invented the nickel-iron battery. the following reaction takes place in the battery. fe(s) + 2 nio(oh)(s) + 2 h2o(l) fe(oh)2(s) + 2 ni(oh)2(aq) how many mole of fe(oh)2, is produced when 5.35 mol fe and 7.65 mol nio(oh) react?

Aperfume bottle is dropped in the corner of a room. the odor of the perfume can be detected on the other side of the room. which statement best describes this observation?

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)