An ammonium buffer solution is prepared by combining 50. mL of 0.20 M ammonia, NH3(aq), and 50. mL of 0.20 M of ammonium chloride, NH4Cl(aq). A 5.0 mL sample of 0.10 M HCl(aq) is added to the buffer solution. Which of the following is a correct pairing of the ammonium species present in greater concentration and of the pH of the solution after the HCl(aq) is added? (The pKb of ammonia is 4.7.)

(A) NH3 < 9.3
(B) NH3 > 9.3
(C) NH4+ < 9.3
(D) NH4+ > 9.3

Maria wants to determine which type of disinfectant kills the most bacteria. which of the following is the best way for maria to determine this? a. ask ten different companies that make disinfectants which type is best. b. put the same amount and species of bacteria on ten identical plates, and add ten different kinds of disinfectant to each plate. c. interview ten different people to determine which type of disinfectant they prefer. d. put the same amount and species of bacteria on ten identical plates, and add a different disinfectant to each plate.

What is the number of atoms in 3.54 mol s

What is the mass of each element in a 324.8 sample of co2