Chem 3 exam

Calculate the energy (in joules) of a single photon of blue light with a frequency of 7.50 x 10^14 Hz. (H = 6.626 x 10^-34 J x s)

(7.50 x 10^14) times (6.626 x 10^-34) equals 4.97 x 10^-19 Joules

In the follow reaction, what quantity in moles of CH3OH are required to give off 1501 kj of heat In the following reaction, what quantity in moles of CH,OH are required to give off 1501 kJ of heat? 2 CH,OH (I) + 3 0, (g) - 2 CO, (g) + 4 H,0 (g) AH° = - 1280. kJ

1501 Kj times 2 mol

In one atom, what is the maximum number of electrons that could have the quantum number of n = 2

2s orbital has 8

What type of calorimeter would be appropriate for measuring heats of combustion

Bomb calorimeter

If a reaction is exothermic, what is true of its reverse reaction

DeltaH > 0

What is the wavelength (in nm) of blue light that has a frequency of 6.69 x 10^14 s-1

Divide constant with frequency to get wavelength in meters then convert to nm (3.00 x 10^8/6.69 x 10^14) = 4.48 x 10^-7 m then to nm by multiplying 10^9 = 448

In which direction on the periodic table does metallic character increase

Down and to the left

Einstein photoelectric effect equation

E = hv

Which of the following metals would be expected to have the smallest atomic radius?

E) Tantalum (Ta)

Which particle would have the longest de Broglie wavelength traveling with the same velocity

Electron

What are isoelectronic species

Elements/ions with the same electron configuration

Which of the following has a heat of formation equaling zero

F2 is in its natural state and natural state have enthalpy of formation that is equal to zero

What is the frequency of green light that has a wavelength of 531 nm? c=3.00 x 10^8

First convert 531 nm to meters (531/10^9) then divide the constant by wavelength. (3.00 x 10^8/5.31 x 10^-7) this gives you frequency

What is the energy of a mole of photons that have a wavelength of 705 nm?

First convert 705 nm to m by dividing 10^9 = 7.05 x 10^-7 m then multiply the c by h and then divide by wavelength = 2.81857 x 10^-19 Joules, then finish by multiplying avogradro's number to find mole of photon (wavelength x avogrados = 1.70 x 10^5 Joules

Determine the energy of a photon with a wavelength of 364 nm

First is to convert 364 nm to m by dividing by 10^9 = 3.64 x 10^-7. Then multiply planck's constant (h) 6.626 x 10^-34 by speed of light (c) 3.00 x 10^8 then divide by wavelength 3.64 x 10^-7 which equals E (5.46x 10^-19 joules

Calculate the frequency in hertz of electromagnetic radiation that has a wavelength of 585.0 nm

First is to convert nm to meters ( 585/ 10^9 ) = 5.85 x 10^-7 then divide constant by this number to get s -1 which is hertz

Halogens tend to form anions because

Gaining electrons will fill their octet faster than losing them

What type of light on the electromagnetic spectrum has the highest energy per photon

Gamma rays

Position and momentum of an electron cannot be know simultaneously with an high degree of accuracy

Heisenberg

Elements that are most similar in their properties are found

In the same group

Greatest effective nuclear charge (Zeff)

Increases from left to right

Which periodic trend quantifies the amount of energy required to remove an electron from a neutral, gaseous atom

Ionization energy

Where does nuclear charge increase

Its increase from left to right Na —-> Ar

Red light has (Blank) frequency and a (Blank) Wavelength than ultraviolet rays

Lower and longer

Which of the following groups of elements tend to form cations

Metals

5 cm wave length is

Microwaves

When an electron in excited energy level drops to a lower energy level, a photon is emitted If the electron is dropping to n=1, which transition will emit the longest wavelength? n=? to n=1

N=2 to n=1

15 m wave length is

Radio waves

What is the lowest energy per photon

Radio waves

which of the following radii comparisons is correct

Solution: Cations are always smaller than the neutral atom from which it is derived. Anions are always larger than the neutral atom from which it is derived. Therefore, the smaller ion in a pair will be the one with fewer electrons

Hess's law can be used to solve for reaction enthalpy changes because enthalpy is a _________ function.

State

If the frequency of a electromagnetic wave decreases, the amplitude will

Stay the same

Photons are shone on a piece of metal and one electron is ejected for each absorbed photon. What happens when the wavelength of light is decreased

The ejected electrons would have greater kinetic energy

A heat of formation is

The heat required to make 1 mole of a compound from its elements in their standard states

Effective nuclear charge, Zeff, is defined as

The true nuclear charge minus the charge that is shielded by electrons

A TT bond could be formed from the overlap of which two orbitals?

Two unhybridized p orbitals

Light wave A has a greater frequency than light wave B. Which has a greater wavelength?

Wave B

Wavelength is defined as when relating to electromagnetic wave as

Wavelength is the distance between two consecutive peaks or troughs in a wave

In one atoms, what Is the maxiumum number of electrons that could have the quantum number of n = 1

When n = 1, there is only the 1s orbital , there can be two electrons in each orbital

A more electronegative atom

Will have more attraction to the electrons in a chemical bond

Which of the following is true concerning ^2 (squared wavefunction)

^2 describes the probability of finding an electron in space

What us the identity of a 100 g sample of metal that, upon absorbing 4680 j of heat, increases in temperature by 52 C

heat (q) 4680 J of heat = 100 g x (c) heat capacity x (delta T) change in temp Q= mcDeltaT Make sure to divide heat by (m and change in temp