Lewis Structures
Describe each of the following components:
Wedge, dashed wedge, solid line, dashed lines
Wedge: covalent bond going out of the page
dashed wedge: covalent bond going into the page
solid line: covalent bond
dashed line: ionic bond/ionic attraction
If the temperature of a gas increases while volume is held constant, what happens to pressure?
pressure increases
Define Molarity
it is concentration or mols of solute per volume (in liters) of solution. M=n/V
What is the Arrhenius definition of an acid and a base
Acid: increases the [H+] concentration in water
base: increases the [OH-] concentration in water
What is electronegativity?
How hard an atom pulls on electrons
Draw the Lewis structure for O2. what is the molecular geometry?
ve- = 12
double bonded O, 2 lone pairs for each O
Geometry = linear
This scientist is associated with the relationship between pressure and volume of a gas at constant temperature.
Boyle's Law
If you add more water to a solution, what happens to its molarity?
Molarity decreases (dilution)
Define a Brønsted–Lowry base and acid.
Base: accepts a proton H+
Acid: donates a proton H+
What are the three most electronegative atoms
F (4.0) O (3.5) N (3.1)
Draw the Lewis structure for HCN. what is the electron and molecular geometry?
EG: linear
MG: linear
A gas has a pressure of 1.2 atm and a volume of 3.0 L. If pressure increases to 2.4 atm at constant temperature, what is the new volume?
V2=1.5L
A student reports a solution has a molarity of 3.0 M. What does this number specifically mean in terms of moles and volume?
There are 3.0 moles of solute per 1.0 liter of solution
What is the primary function of a buffer
To resist changes in pH
Calculate the electronegativity difference between carbon (2.5) and oxygen (3.5). What does this suggest about the type of bond?
polar covalent (EN=1.0)
Draw the Lewis structure for NO3-. Draw two additional resonance structures. What's the electron and molecular geometry?
EG: Trigonal planner
MG: Trigonal planner
A 2.0 mol sample of gas is in a 10.0 L container at 300 K. What is the pressure? (R = 0.0821 L·atm/mol·K)
P=4.92 atm
How many moles are in 0.50 L of a 2.0 M solution?
n= 1 mol
A solution has [H+] =1.0×10-3. What is the pH?
pH=3
calculate the electronegativity in the bonds of CO₂, is it a polar or nonpolar molecule? Explain why
though the bonds are polar, the molecular geometry cancels out the polarity making the molecule non-polar.
Draw the Lewis structure of SO32-. draw two additional resonance structures. what is its electron and molecular geometry?
EG: tetrahedral
MG: Trigonal Pyramidal
A 1.50 mol sample of gas occupies 12.0 L at a pressure of 2.00 atm and a temperature of 300 K. What is the value of R based on this data?
R=0.0533 L·atm/mol·K
A student dissolves 10.0 g of NaCl (58.44 g/mol) and makes the solution up to 250 mL. What is the molarity of the solution?
M ≈ 0.684 M
A solution has [OH-]=1.0×10-5 M. what is the pH?
How does electronegativity influence the accuracy of resonance structures?