Exam (elaborations)
BCH 371 - Exam 1 (Ch. 2-5) questions and correct answers
- Course
- Institution
BCH 371 - Exam 1 (Ch. 2-5) questions and correct answers
[Show more]
Content preview
BCH 371 - Exam 1 (Ch. 2-5)True or False: H-Bond is stronger when the three atoms involved in the bon lie at an angle - correct
answer ✔✔False; Hydrogen bonds are much stronger in a linear fashion - straight
How many H-bonds does water molecule make with neighboring water molecule in liquid and solid
forms? - correct answer ✔✔Liquid: watch water molecule hydrogen bonds with an average of 3.4 other
water molecules
Solid: each water molecule forms 4 hydrogen bonds - the
What are micelles? Which biomolecules are found in this form? - correct answer ✔✔High concentration
of amphipathic molecules aggregate into micelles. Phospholipids dispersed in a liquid form a colloidal
suspension
Name four types for noncovalent interaction found among biomolecules in aqueous solvents. - correct
answer ✔✔Ionic Interactions: electrostatic interactions between permanently charged species, or
between the ion and a permanent dipole.
Van der Waals: weak interactions between al atoms, regardless of polarity. Attractive (dispersions) and
repulsive (steric) component
Hydrophobic effect: complex phenomenon associated with the ordering of water molecules around
nonpolar substances
Dipole interactions: electrostatic interaction between uncharged but polar molecules
What is the concentration of -OH in a solution of 0.24M HCl? - correct answer ✔✔
, Solution A has a pH of 8 and solution B is 10^7 times more acidic than solution A. What will be the pH of
solution B? (hint: 1pH unit change = 10 times change in H+ concentration, higher H+ = lower pH) - correct
answer ✔✔
Weak acid and its conjugate base (H2PO4- / HPO4^2-) has a pKa of 6.86. What would be the best
buffering range for this?
a. pH 6-7
b. pH 8.3 - 10.3
c. pH 5.9-7.9
d. pH 4-8 - correct answer ✔✔a. pH 6-7
Work example 2-6 (a) (pg. 66) - correct answer ✔✔
End chapter problems: 11,13,14 (pg 70) - correct answer ✔✔
Hydrogen Bonds - correct answer ✔✔Are strong dipole-dipole or charge-dipole interactions that arise
between a covalently bound hydrogen and lone pair of electrons.
Typically involve two electronegative atoms (frequently nitrogen and oxygen)
Hydrogen bonds are strongest when the bonded molecules allow for linear bonding patterns (in a line)
Hydrogen bonds in water - correct answer ✔✔Water can server are both, an H donor, an H acceptor.
Hydrogen bonding in water is cooperative.
Up to four bonds per water molecule gives water its: anomalously high boiling point, anomalously high
melting point, unusually large surface tension.
Hydrogen bonds between neighboring molecules are weak, relative to the H-O covalent bonds
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Sakayobako30. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $14.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
72042 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now
