Photoelectric Effect
What determines the work function of a substance?
The strength of the attraction between the nucleus and electrons.
Orbitals that are equal in energy are referred to as __________.
Degenerate
What is the key difference between a ribonucleotide & a deoxyribonucleotide?
Ribonucleotides have a hydroxide at the 2' carbon while deoxyribonucleotides simply have an H atom
Draw the lewis structure of COCl2
C with single bonds for the Cl atoms (3 LPs each) and a double bond for the O atom (2 LPs)
Explain the difference between molar ratio, molar volume, and molar mass.
Molar ratio
Molar volume
Molar mass
In the photoelectric effect experiment, the frequency of light determines the ______________ per particle of light. The intensity (amplitude) determines the _______________ of particles.
In the photoelectric effect experiment, the frequency of light determines the energy per particle of light. The intensity (amplitude) determines the number of particles.
Which atom has the following electron configuration:
1s22s22p63s23p2
Si
What is the direction of DNA replication?
The new strand is built ____ to ____, and the old, template strand is read ____ to ____.
The new strand is built 5' to 3', and the old, template strand is read 3' to 5'.
Draw the lewis structure(s) for N3-
N triple bond N single bond N
N single bond N triple bond N
N double bond N double bond N
How many grams of magnesium nitride is required to produce 25g of magnesium hydroxide? Mg3N2+H2O→Mg(OH)2+NH2
14.42g
Draw a diagram of the photoelectric effect
See key
What is the electron configuration of Cl?
[Ne]3s23p5
Why does the lagging strand need to loop around during DNA replication?
So that both the leading and lagging strand DNAPs can read their repsective sequences 3'-5' and construct the new strand 5'-3', while moving in the same direction at the same rate.
Draw the lewis structure for NO
N (1 LP and 1 unpaired) double bond O (2 LPs)
In lab you produce 27.9 g of PBr3 from 35.0 g of Br2 with excess P.
Balance the equation: __Br2 + __P → ___PBr3
What is your percent yield?
3 Br2 + 2 P → 2 PBr3
70.6% yield
Why must light be both a wave and particle?
It allows it to have 2 types of energy (wavelength and "packet" of energy). To explain this, we must describe light as a wave and a particle.
Consider the process of shielding in atoms. What is being shielded? What is it being shielded from? What is doing the shielding?
Electrons in lower orbitals shield electrons in further orbitals from the positive charge of the nucleus.
What are some of the benefits of DNA's tendency to form a double helix? List at least 3.
Stability, protects the genetic code, buries the hydrophobic bases, saves space, more obvious when mistakes are made (misshapen helix, repair enzymes recognize)
Draw the lewis structure for beryllium dichloride. What is this structure's geometry (include bond angles)
(3LPs)Cl-Be-Cl(3LPs)
Linear, 180
You only have 200g of carbon monoxide. How much methanol (CH3OH) can you make? Assume that you have an infinite supply of hydrogen gas.
CO(g) + 2H2 (g) → CH3OH(l)
229g CH3OH
Calculate the energy and wavelength of light emitted from a hydrogen atom when there is a transition from n=4 → n=1.
E = 2.04 x 10-18 J
97nm
What is the difference between electron affinity and electronegativity?
Electron affinity is an atom's ability to attract electrons. Electronegativity is an atom's ability to draw electrons towards itself within a bond.
Diagram the steps of DNA replication
See key
Draw the lewis structure for H3PO4 ....What is the molecular geometry?
Phosphoric acid (see key)
Tetrahedral
You need to make 10.0 L of 1.2 M KNO3. What molarity would the potassium nitrate stock solution need to be if you were to use only 2.5 L of it?
4.8M