LS7A Practice Exam Questions and
Answers Graded A+
Which of the following molecules is held together by polar covalent bonds?
CH4, KCl, NH3 - Correct answer-NH3
How many hydrogen atoms are present in a hydrocarbon chain of five carbon
atoms with two double bonds and two single bonds? - Correct answer-8
Which of the following molecules is held together by nonpolar covalent bonds?
KCl, CH4, NH3 - Correct answer-CH4
Which of the following molecules is held together by ionic bonds?
KCl, CO2, NH3 - Correct answer-KCl
Three carbon atoms are linked by single covalent bonds such that they form the
shape of a V. All of the unshared electrons form covalent bonds with hydrogen.
How many hydrogen atoms does this molecule contain? - Correct answer-8
Molecule X contains at least one nonpolar covalent bond
CH3CO2 - Correct answer-True
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, Molecule X could form a hydrogen bond with water
CH3CO2 - Correct answer-True
Molecule X could form a hydrogen bond with another Molecule X
CH3CO2 - Correct answer-False
Molecule X could form an ionic bond with Na+
CH3CO2 - Correct answer-True
Molecule X could form an ionic bond with Cl-
CH3CO2 - Correct answer-False
Why does a phospholipid on the cytoplasmic side of the cell membrane rarely flip
to the extracellular side if both environments are polar? - Correct answer-The polar
head group cannot pass through the nonpolar interior.
The beaker in the illustration below contains two solutions of salt with different
concentrations (measured by molarity, M). The two solutions are separated by a
membrane that is permeable to both salt and water.
0.2 M salt A, 0.9 M salt B
Which of the following will you observe after a long time has passed? - Correct
answer-No net diffusion of water or salt across the membrane.
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Answers Graded A+
Which of the following molecules is held together by polar covalent bonds?
CH4, KCl, NH3 - Correct answer-NH3
How many hydrogen atoms are present in a hydrocarbon chain of five carbon
atoms with two double bonds and two single bonds? - Correct answer-8
Which of the following molecules is held together by nonpolar covalent bonds?
KCl, CH4, NH3 - Correct answer-CH4
Which of the following molecules is held together by ionic bonds?
KCl, CO2, NH3 - Correct answer-KCl
Three carbon atoms are linked by single covalent bonds such that they form the
shape of a V. All of the unshared electrons form covalent bonds with hydrogen.
How many hydrogen atoms does this molecule contain? - Correct answer-8
Molecule X contains at least one nonpolar covalent bond
CH3CO2 - Correct answer-True
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, Molecule X could form a hydrogen bond with water
CH3CO2 - Correct answer-True
Molecule X could form a hydrogen bond with another Molecule X
CH3CO2 - Correct answer-False
Molecule X could form an ionic bond with Na+
CH3CO2 - Correct answer-True
Molecule X could form an ionic bond with Cl-
CH3CO2 - Correct answer-False
Why does a phospholipid on the cytoplasmic side of the cell membrane rarely flip
to the extracellular side if both environments are polar? - Correct answer-The polar
head group cannot pass through the nonpolar interior.
The beaker in the illustration below contains two solutions of salt with different
concentrations (measured by molarity, M). The two solutions are separated by a
membrane that is permeable to both salt and water.
0.2 M salt A, 0.9 M salt B
Which of the following will you observe after a long time has passed? - Correct
answer-No net diffusion of water or salt across the membrane.
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