Quiz 3: Moles, EM Spectrum, and Quantum Theory

(1 x 22.990 amu) + (1 x 35.453 amu) = 58.443 amu

What is the Average Atomic mass of NaCl?

(1 x 32.065 amu) + (2x 15.999amu) = 64.063 amu

64.063 amu/1 molecule = 64.063 g/mol

What is the Molar Mass (MM) of SO2?

MM = 110.984 g/mol

5.12 x 10^-7 mol x (110.984 g / 1 mol) x (1 Mg / 10^-6 g)

= 56.8 Mg

5.12 x 10^-7 mol CaCl2 →

______ mass in Mg

Avogadro's Number (n)

6.0221 x 10^23 particles/1 mol

To convert moles into molecules, you must use ________________

Avagadros number (n)

What equation is this:

6.0221 x 10^23 particles/1 mol

0.166 mol CO2 x (6.0221 x 10^23 CO2 molecules) / 1 mol CO2

= 9.99 x 10^22 CO2 molecules

0.166 mol CO2 →

______ CO2 molecules

12.011 + (2 x 35.453) + (2 x 18.918) = 120.913 amu

120.913 amu/ 1 molecule →

120.913 g/mol

Molar Mass (MM) of CCl2F2?

5.48 kg x (10^3 g/ 1 kg) x (1 mol/ 120.913 g)

= 45.3 mol

5.48 kg ->

______ mols of CCl2F2

45.3 mol x (6.0221 x 10^23 molecules) / 1 mol

= 2.73 x 10^25 molecules

5.48 kg ->

______ molecules of CCl2F2?

speed of light = wavelength x frequency (m/s = m x s^-1)

To solve for wavelength, you must use ___________

Frequency (V)

_____________ is the number of oscillations per second, measured in Hz (s^-1)

Speed of Light (C)

What is this equation:

2.998 x 10^8 m/s

0.111 cm x 10^-2 m/1 cm

= 0.00111 m

C = wavelength x V

(2.998 x 10^8 m/s) = 0.00111m x V

V = 2.70 x 10^11 Hz

(2.70 x 10^11 Hz) x 1 MHz / (10^6 Hz)

= 2.70 x 10^5 MHz

0.111 cm → _____ MHz (megahertz)

1240 KHz x (10^3 Hz/ 1 KHz) = 124 x 10^6 Hz

C = wavelength x V

2.998 x 10^8 m/s = wavelength x (1.24 x 10^6 s^-1)

Wavelength = 242m

1240 KHz → ______ wavelength in m?

Amplitude

The ____________ is the brightness of light in electromagnetic waves

Continuous Spectrum

The _________________ is an unbroken distribution of light across wavelengths

Continuous Spectrum

The EM spectrum is an example of a ___________________

Atomic Spectrum

The _______________ is a group of unique wavelengths emitted by elements when excited

Atomic Spectrum

Black lines (Fraunhofer Lines) in the absorption spectrum correspond to wavelength of light in the _____________________

Quantized energies

The Atomic spectrum is evidence that electrons have __________________

Discrete energy

Quantized energy is ___________________

Energy of 1 photon = (plancks constant x speed of light) / wavelength

What does each variable in the equation stand for?

Planck's Constant (h)

What is this equation:

6.626 x 10^-34 JS

520 nm x (10^-9 m/1 nm) = 5.20 x 10^-7 m

E = (6.626 x 10^-34 JS) (2.998 x 10^8 m/s)/ 5.20 x 10^-7 m

E = 3.83 x 10^-19 J

Green laser pointer emits light at 520 nm

What is the energy of 1 photon of light at the wavelength?

Quantum Theory

The ________________ describes quantized energy levels of electrons

Bohr Model

The ______________ explains electron energy levels in hydrogen

Change in energy

Bohr model:

ΔE = -2.178 x 10^-8 J ( 1/n^2 Final - 1/n^2 Initial) solves for ____________

ΔE = -2.178 x 10^-8 J ( 1/1^2 Final - 1/2^2 Initial)

ΔE = -2.178 x 10^-8 J ( 4/4 Final - 1/4 Initial)

ΔE = -2.178 x 10^-8 J ( 3/4)

ΔE = -1.634 x 10^-18 J

Bohr model:

Electron gets excited from n = 1 to n = 2

What is the energy released when electron returns to n = 1

n Initial = 2 n Final = 1

True

True or False:

A negative outcome from the Bohr model tells us that energy has been released (positive - energy has been absorbed)

n = 1

_____________ is the lowest energy orbit

H (hydrogen)

E (energy) of transmission corresponds to a band on the atomic structure of __________ only

H has 1 electron, more than one electron makes things more complicated

Why does the E (energy) of transmission only work with H (hydrogen)?

- h -> Plancks constant

- m -> mass

- v -> velocity

h/mv is the De Broglie Wavelength

- h stands for ______________

- m stands for _______________

- v stands for _______________

momentum

mv (mass x velocity) --> __________________

Wavelength

As mass increases, ________________ decreases

Heisenberg Uncertainty Principle

- location

________________ states that you cannot know both the position and momentum of an electron at the same time. The focus in on the probable _____________ of the electron

1. Principle (n)

2. Angular momentum (L)

3. Magnetic (m L)

4. Spin (m s)

There are four Quantum numbers describing the electron's energy and position. What are they?

Orbital

Each __________ is described by 4 Quantum numbers

Principal (n)

Quantum numbers:

The _______________ tells us the size and energy level of an orbital

Angular Momentum (L)

Quantum numbers:

The ____________ tells us the shape of an orbital

0 to n-1

L can equal _______________

Magnetic (m L)

Quantum numbers:

The ________________ tells us the orientation of an orbital (divides the subshells and orbitals)

-L to +L (Integers)

m L can equal _____________

Spin (m s)

Quantum numbers:

The _____________ describes the electron spin

+½ or -½

m s can be _______________

Pauli Exclusion Principle

The ______________ Tells us that no electrons in the same atom can have identical quantum numbers

2

The Pauli Exclusion Principle states that each orbital can hold a max of ________ electrons

Electrons (2 max)

______________ will have opposite spins if in the same orbital

True

True or False:

To find the max number in electrons multiply number of orbitals by 2 (max electrons)

S orbital

Which orbital is shown here?

p orbital

Which orbital is shown here?

d orbital

Which orbital is shown here?

E -> Energy of one photon of light

h -> planks constant (6.626 x 10^-34 J S)

V -> frequency

E = hV is the ____________________

h stands for ______________

V stand for _______________

Photons

Light exists by waves and packets of energy called ____________