Homework answers / question archive / Gateway Technical College BIO 806-177 Lecture 2 : Water 1)In which of the following are the types of interactions sorted from STRONGEST to WEAKEST? Dipole-Dipole, Covalent interactions, Van Der Waals Dipole-Dipole, Van Der Waals, Covalent Interactions Covalent Interactions, Dipole-Dipole, Van Der Waals Van Der Waals, Dipole-Dipole, Covalent Interactions Given what you know about nonbonded interactions, which of the following do you expect to have the lowest boiling point? Methane (CH4) Methanol (CH3OH) Methylamine (CH3NH2) Formaldehyde (CH2O) Which of the following statements about hydrogen bonding in water is TRUE? An average water molecule <4 hydrogen bonds as ice and <4 as a liquid An average water molecule make <4 hydrogen bonds as ice and 4 as a liquid An average water molecule makes 4 hydrogen bonds as ice and 4 as a liquid An average water molecule makes 4 hydrogen bonds as ice and <4 as a liquid Which of the following molecules have BOTH a hydrogen bond donor and acceptor? Formaldehyde (CH2O) Methanol (CH3OH) Methylamine (CH3NH2) Ethane (C2H6) Hydrophobic molecules (like oil) tend to self-associate in water rather than dissolve

Gateway Technical College BIO 806-177 Lecture 2 : Water 1)In which of the following are the types of interactions sorted from STRONGEST to WEAKEST? Dipole-Dipole, Covalent interactions, Van Der Waals Dipole-Dipole, Van Der Waals, Covalent Interactions Covalent Interactions, Dipole-Dipole, Van Der Waals Van Der Waals, Dipole-Dipole, Covalent Interactions Given what you know about nonbonded interactions, which of the following do you expect to have the lowest boiling point? Methane (CH4) Methanol (CH3OH) Methylamine (CH3NH2) Formaldehyde (CH2O) Which of the following statements about hydrogen bonding in water is TRUE? An average water molecule <4 hydrogen bonds as ice and <4 as a liquid An average water molecule make <4 hydrogen bonds as ice and 4 as a liquid An average water molecule makes 4 hydrogen bonds as ice and 4 as a liquid An average water molecule makes 4 hydrogen bonds as ice and <4 as a liquid Which of the following molecules have BOTH a hydrogen bond donor and acceptor? Formaldehyde (CH2O) Methanol (CH3OH) Methylamine (CH3NH2) Ethane (C2H6) Hydrophobic molecules (like oil) tend to self-associate in water rather than dissolve

Biology

Share With

1)In which of the following are the types of interactions sorted from STRONGEST to WEAKEST?

1. 1. Dipole-Dipole, Covalent interactions, Van Der Waals
   2. Dipole-Dipole, Van Der Waals, Covalent Interactions
   3. Covalent Interactions, Dipole-Dipole, Van Der Waals
   4. Van Der Waals, Dipole-Dipole, Covalent Interactions
2. Given what you know about nonbonded interactions, which of the following do you expect to have the lowest boiling point?
   1. Methane (CH4)
   2. Methanol (CH3OH)
   3. Methylamine (CH3NH2)
   4. Formaldehyde (CH2O)
3. Which of the following statements about hydrogen bonding in water is TRUE?
   1. An average water molecule <4 hydrogen bonds as ice and <4 as a liquid
   2. An average water molecule make <4 hydrogen bonds as ice and 4 as a liquid
   3. An average water molecule makes 4 hydrogen bonds as ice and 4 as a liquid
   4. An average water molecule makes 4 hydrogen bonds as ice and <4 as a liquid
4. Which of the following molecules have BOTH a hydrogen bond donor and acceptor?
   1. Formaldehyde (CH2O)
   2. Methanol (CH3OH)
   3. Methylamine (CH3NH2)
   4. Ethane (C2H6)
5. Hydrophobic molecules (like oil) tend to self-associate in water rather than dissolve. What is the MAJOR energetic contribution to this property?
   1. The self-association maximizes the entropy of the oil molecules
   2. The self-association minimizes the enthalpy of the oil molecules
   3. The self-association minimizes the enthalpy of oil/water interactions
   4. The self-association maximizes the entropy of the water molecules
6. The pKa of acetic acid (CH3COOH) is 4.76. What is the ratio of [CH3COO-] to [CH3COOH] at a pH of 6.76? a.       100:1

b.   2:1

c.     1:2

d.  1:100

7. Sort the pH of the following mixtures (most acidic) to highest (most basic):

• (I) 0.001 mol of HCl added to 1L water
• (II) 0.001 mol of HCl added to a buffer solution of 0.1M HCOOH and 0.1M NaHCOO (pKa = 3.75)
• (III) 0.001 mol of HCl added to a buffer solution of 0.1M NH4Cl and NH3 (pKa = 9.25)
  1. I, II, III
  2. II, I, III
  3. II, III, I
  4. III, II, I

8. Which of the following statements is TRUE about a protein with an isoelectric point (pI) of 5.5?
   1. It has a net negative charge at pH 4 and net negative charge at pH 9
   2. It is neutral at pH 4 and has a net negative charge at pH 9
   3. It has a net negative charge at pH 4 and net positive charge at pH 9
   4. It has a net positive charge at pH 4 and net negative charge at pH 9