Semester 2 Review Flashcards
What does temperature measure?
The average kinetic energy of particles in a sample of matter
Explain what is meant by the terms exothermic and endothermic
Exothermic is when a substance gives off heat, endothermic is when a substance absorbs heat.
What is meant by the specific heat capacity of a material?
Specific heat is the amount of heat required to raise the temp of one gram of that substance to 1 degree C
Calculate the mass (in grams) of each of the following substances that could be warmed over the indicated
temperature range by application of exactly 1.0 kJ of energy. (1.0 kJ = 1000J)
a. water, from 15°C to 42°C s=4.184 J/g °C
b. iron, from 25°C to 125°C s=0.45 J/g °C
c. carbon, from -10°C to 47°C s=0.71 J/g °C
a. 1000J/(4.18427°C)=8.85gH2O b. 1000J/(.45100°C)=22.2gFe
c. 1000J/(.71*57°C)=24.7gC
How many s,p,d and f orbitals can occupy any given energy level?
S-1, P-3, D-5, F-7
How many electrons can occupy an orbital at any given energy level?
2 electrons per orbital
What is the shape of a p-orbital? S-orbital?
P orbital- dumbbell shaped
S orbital- sphere shaped
What is the lowest energy level that can have a p-orbital? D-orbital? F-orbital?
P-orbital level 2
D-orbital level 3
F-orbital level 4
Is it possible for two electrons in the same atom to have exactly the same set of quantum numbers?
No, no two electrons can have the same quantum numbers
When is an electron configuration considered stable
When the subshells are full
Distinguish between an atom in its ground state and an excited atom
An atom in ground state had the lowest possible energy and an atom in excited state has gained energy
What happens when a photon of light is emitted?
A photon of light emits when an electron goes from excited states back to ground state
For the following elements list the electron configuration.
a. oxygen, cesium, krypton, titanium, scandium, nitrogen, chlorine
a. oxygen [He]2s2 2p4
1 cesium [Xe]6s
2 10 6 krypton [Ar]4s 3d 4p
22 titanium [Ar]4s 3d
21 scandium [Ar]4s 3d
23 nitrogen [He]2s 2p
25 chlorine [Ne]3s 3p
Define electronegativity
Electronegativity is the ability of an atom to attract electrons
Does electronegativity increase or decrease as the atomic number of an element increases within the same
period of the periodic table?
Electronegativity increases as atomic number increases. It increases from left to right across the periodic
table.
How is the strength of a bond between two elements in a molecule related to their electronegativities?
If the difference in electronegativities of two different atoms is very big, they will have a strong bond. If
the difference in electronegativities is very small, they will have a weaker bond.
What is the difference between an ionic and a covalent bond?
An ionic bond is between a metal and a non-metal. Great electronegativity difference.
A covalent bond is
between two non-metals. Very small electronegativity difference
Referring to the table of electronegativities, classify each of the following bonds as either ionic (I) or
covalent (C):
a.Al-Of
b. Al-S
c. Bi-Cl
d. Bi-O
e. C-Cl
f. N-O
g. Na-S
h. P-O
i. S-O
j. Ti-Br
k. Ca-F
l. Ba-S
Ia.Al-O Cb.Al-S Cc.Bi-Cl Cd.Bi-O Ce.C-Cl Cf.N-O Ig.Na-S Ch.P-O Ci.S-O I j.Ti-Br Ik.Ca-F Il.Ba-S
What atoms forms diatomic molecules
Br2 I2 N2 Cl2 H2 O2 F2
Give an example of a polar covalent and a non polar covalent molecule
Polar covalent-two different atoms C-H
Non-polar- same atom N=N
What does VSEPR stand for?
Valance Shell Electron Pair Repulsion
What does the VSEPR theory predict?
It predicts the shape of molecules
Draw the Lewis dot structure for SiO2
O=Si=O
Convert 1.20 atm to units of mmHg, torr and pascals
1.20 atm * 760mmHg/1atm = 912 mmHg 1.20 atm * 760 torr/1atm = 912 torr
1.20 atm * 101,325 Pa/ 1atm= 121590 Pa
What does STP stand for? What conditions correspond to STP?
Standard Pressure Temperature
STP= 0*C and 1 atm
As temperature increases at constant pressure, what happens to volume?
Volume increases
How is the concept of energy defined?
The ability to do work
As a temperature increases at constant pressure, what happens to the volume?
The volume increases
As volume increases at a constant temperature , what happens to the volume?
Volume decreases
Define molar heat of fusion and molar heat of vaporization
Molar heat of fusion is the energy required to melt 1 mol of a substance
Molar heat of vaporization is energy required to change 1 mol of liquid to its vapor
What is dipole-dipole attraction? What is hydrogen bonding?
Molecules whose positive and negative ends attract.
Hydrogen bonding is when nitrogen, fluorine, and oxygen interact
Define London dispersion forces
Forces they exist between noble gases an non polar molecules
What is vaporization?
What is condensation?
Vaporization is where liquid forms to make a gas
Condensation is where vapor molecules form a liquid
Energy _as a substance goes from liquid to gas
Increases
Energy _ as a substance goes from liquid to solid
Decrease
How are kinetic energy and temperature related?
Temperature is a measure of the average kinetic energy
Define homogenous and heterogenous mixtures
Heterogenous-mixture of two or more substances in same state.(oil and water)
Heterogenous mixture -mixture of two or more substances in different states (sand and water)
What is a saturated, unsaturated and supersaturated solution?
Saturated- when a solution contains as much solute as will dissolve
Unsaturated- solution has not reached lint of solute
Supersaturated-contains more dissolved solid than a saturated solution can hold
What is molarity?
Concentration of solute in solvent measured in mol/L
What are the properties of and acids and bases
Acids- sour and turn litmus paper red
Bases-bitter, slippery, and turn litmus paper blue
What is the pH of an acidic solution?
1-6
What is the pH range of a base?
8-14
When an acid and a base are mixed what are the results?
Water and salt
What are the Arrhenius and Bronsted-Lowry definitions of acids and bases?
Arrhenius said acids produce H+ while bases produce OH-
Bronsted-Lowry said an acid is a proton donor while base is proton receptor
What is a buffered solution?
A solution that resists change in pH. (ex) a weak acid and a conjugate base
What do we mean by an equilibrium position?
It’s where the equilibrium lies, if there are more products than reactants (equilibrium lies to the right)
More reactants than products ( lies to the left)
What is a catalyst?
A Catalyst lowers activation energy in a reaction
What are four factors that affect reaction rate
Surface area, temperature, stirring and nature of reactants
What is Le Chatelier’s principle?
When a change is imposed on a system at equilibrium, the position of the equilibrium shifts In a direction that tends to reduce the effects of change.
