객관식
What is the percent by mass of water in Na2SO4 · 10H2O?
156
views
3. Chemical Reactions
Mass Percent
객관식
What is the mass percent of carbon (C) in C2H6O (ethanol)? Provide your answer to two decimal places.
A
44.44%
B
52.14%
C
34.78%
D
60.00%
검증된 단계별 안내1
Identify the molecular formula of ethanol, which is C\_2H\_6O, meaning it contains 2 carbon atoms, 6 hydrogen atoms, and 1 oxygen atom.
Find the atomic masses of each element from the periodic table: carbon (C) is approximately 12.01 g/mol, hydrogen (H) is about 1.008 g/mol, and oxygen (O) is about 16.00 g/mol.
Calculate the molar mass of ethanol by summing the contributions of each element: multiply the number of atoms of each element by its atomic mass and add them together: \(\text{Molar mass} = (2 \times 12.01) + (6 \times 1.008) + (1 \times 16.00)\).
Calculate the total mass of carbon in one mole of ethanol by multiplying the number of carbon atoms by the atomic mass of carbon: \(\text{Mass of C} = 2 \times 12.01\).
Determine the mass percent of carbon by dividing the total mass of carbon by the molar mass of ethanol and multiplying by 100: \(\text{Mass \% C} = \left( \frac{\text{Mass of C}}{\text{Molar mass of ethanol}} \right) \times 100\).
관련 영상
관련 실천
