I think the answer is B . I really hope that this helps you out.
You have 0.50 mol of NH3 and 0.20 mol of NH4+ to start (NH4Cl dissolves completely), given the molarity and 1.0 L solution.
30.0 mL of 1.0 M HCl is 0.0300 mol of HCl. This will react with the NH3 to produced 0.030 mol of NH4+.
You now have 0.47 mol NH3 and 0.23 mol NH4+. Now use the Henderson-Hasselbach equation to calculate your pH. The equation says to use concentration of acid and base, but you can just use the moles of them because it doesn’t make a difference.
pH = pKa + log(base/acid)
pKa = 14 - pKb = 14 - 4.75 = 9.25
pH = 9.25 + log(0.47/0.23) = 9.56
Missing question:
A. All carbon atoms are identical.
B. An oxygen atom combines with 1.5 hydrogen atoms to form a water molecule.
C. Two oxygen atoms combine with a carbon atom to form a carbon dioxide molecule.
D. The formation of a compound often involves the destruction of one or more atoms.
Answer is: B and D.
A is correct because Daltan stated: All atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements.
C is correct because atoms combine in simple, whole- number ratios to form compounds, B is incorrect because ratio is not simple, whole number.
D is incorrect because according to Dalton. atoms can't be created or destroyed.
B) brings order to the elements. This is correct because elements are in order by highest atomic number.
