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.

Consider a culture medium on which only gram-positive organisms such as staphylococcus aureus colonies can grow due to an elevated nacl level. a yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the ph as a result and changing the color of a ph indicator chemical. this type of medium would be referred to as a differential and enrichment culture.