객관식
What is the percent by mass of hydrogen in NH_3 if the gram formula mass is 17.0 grams?
114
views
3. Chemical Reactions
Mass Percent
객관식
Codeine has the molecular formula C17H19NO3. What is the mass percent of carbon (C) in codeine?
A
67.9%
B
41.7%
C
54.2%
D
75.3%
검증된 단계별 안내1
Identify the molecular formula of codeine: C17H19NO3. This tells us there are 17 carbon atoms, 19 hydrogen atoms, 1 nitrogen atom, and 3 oxygen atoms in one molecule of codeine.
Find the atomic masses of each element involved: Carbon (C) = 12.01 g/mol, Hydrogen (H) = 1.008 g/mol, Nitrogen (N) = 14.01 g/mol, Oxygen (O) = 16.00 g/mol.
Calculate the total molar mass of codeine by multiplying the number of atoms of each element by their atomic masses and summing all contributions: \(\text{Molar mass} = (17 \times 12.01) + (19 \times 1.008) + (1 \times 14.01) + (3 \times 16.00)\).
Calculate the total mass of carbon in one mole of codeine by multiplying the number of carbon atoms by the atomic mass of carbon: \(\text{Mass of C} = 17 \times 12.01\).
Calculate the mass percent of carbon by dividing the total mass of carbon by the molar mass of codeine and multiplying by 100: \(\text{Mass \% C} = \left( \frac{\text{Mass of C}}{\text{Molar mass of codeine}} \right) \times 100\).
관련 영상
관련 실천
