Chapter E, 1, 2, and 3 Chemistry Structure and Properties by Nivaldo J Tro

Exa or E

10^18

peta or P

10^15

tera or T

10^12

giga or G

10^9

mega or M

10^6

kilo or k

1000 or 10^3

deci or d

0.1 or 10^-1

centi ot c

0.01 or 10^-2

milli or m

10^-3

micro or μ

10^-6

nano or n

10^-9

pico or p

10^-12

femto or f

10^-15

atto or a

10^-18

measurement

is a comparison between an unknown quantity to a known quantity called a unit

mass

the amount of matter in an substance

Energy

the ability to do work

When does work occur?

when a force acts through a distance

PE

is the energy an object has because of its position

KE

energy of motion

KE= .5mv^2

m-kg

v-m/s

Law of Conservation of Energy

Energy cannot be created or destroyed

speed

distance/time

1 Joule

1 kg m^2/s^2

1 Calorie

1000 calories

Thermal Energy

The energy an object has due to the motion of the atom and molecules in that object

Temperature

A measure of the average KE of the particles that make up a substance

Heat

The energy transferred between objects that are at different temperatures

Kelvin to C

K=C+273.15

C to F

C=(F-32)/1.8

volume

LxWxH

Accuracy

is a measure of how close the measurement is to the true value

precision

refers to how close a series of measurements are to one another

Trial A 10.49

Trial B 9.79

Trial C 9.92

Trial D 10.31

Average 10.31

Precision or accurate?

Inaccurate(not close to the true value) and imprecise(not consistent with one another) might be due to random error probability is either too high or too low

Trial A 9.78

Trial B 9.82

Trial C 9.75

Trial D 9.80

Average 9.79

Precision or accurate?

precise but inaccurate

systematic error- error that is too high or too low

Trial A 10.03

Trial B 9.99

Trial C 10.03

Trial D 9.98

Average 10.01

Precision or accurate?

Accurate and precise- little systematic and random error

Rule for significant figures

1. all non zero numbers are significant

2. Internal zeros are always significant

3. Leading zeros are not significant (0.00002)

4. Trailing zeros

A) after the decimal are significant

B) before a decimal point they are significant

C) before an implied decimal point not significant (1200)

scientific notationn 1479

1.479*10^3

Density

mass/volume

An automobile gasoline tank holds 20 kg of gasoline. When the gasoline burns, 82 kg of oxygen is consumed and carbon dioxide and water are produced. What is the total combined mass of carbon dioxide and water that is produced?

20+82=102 kg

The mass ratio of sodium to fluorine in sodium fluoride is 1.21:1. A sample of sodium fluoride produced 29.2 g of sodium upon decomposition.

29.2/1.21=24.1g

Calculate the mass (in g) of 2.0 × 10^24 atoms of Hg.

(2.0x10^24)/(6.022x10^23) x200 (find atomic mass on periodic table=6.5x10^2

significant figures 408

3sf

sf 140.000

6 sf

sf 1.2*10^3

2 sf

sf 1200

4 sf

An FM radio station broadcasts electromagnetic radiation at a frequency of 90.2 MHz. The wavelength of this radiation is ________ m.

v=90.2*10^6 Hz

wavelength=c/v

wavelength=3.00*10^8/90.2*10^6

wavelength=3.33

How many photons are contained in a burst of yellow light (589 nm) from a sodium lamp that contains 609 kJ of energy?

First u find the energy of each photon

E= hc/wavelength

= (6.626x10^-34 x 3 x 10^8)/ 589 x 10^-9 = 3.74 x 10^-19Joules

then u divide the total energy by the energy of each

609000 Joules / 3.74 x 10^-19Joules

which gives you 1.80 X 10(24) photons

When a wave encounters an obstacle or a slit that is comparable in size to its wavelength, it bends around it. This characteristic is called ________.

diffraction

Calculate the frequency of the green light emitted by a hydrogen atom with a wavelength of 486.1 nm.

c = wavelength(landa)*frequency

3.00*10^8/(486.1*10^-9)

Determine the lowest frequency of light capable to remove an electron from a sample of Ti metal, if the binding energy of titanium is 3.14 × 103 kJ/mol.

First get the binding energy down to one atom of Ti

3.14 x l0^3 Kj/mole over 6.02 x l0^23 atoms/mole = 5.22 x l0^-21 kj/atom

or 5.22 x l0^-18th joules per atom ( I multiplied by l000 to get joules from Kj)

Energy per photon = Planck's constant times frequency

frequency = energy per photon over Planck's constant

frequency = 5.22 x l0^-18th over 6.63 x l0-34th

frequency = 7.87 x l0^15th waves per second

Arrange the following types of electromagnetic radiation in order of increasing wavelength (shortest to longest): microwaves, gamma rays, ultraviolet, and infrared.

Gamma rays, ultraviolet, infrared, and microwaves

Determine the mass of a ball with a velocity of 42.5 m/s and a wavelength of 8.92 × 10-34 m.

m=h/mv

(6.625*10^-34)/(8.92*10^-34)(42.5)

time 1000 to get g

17.5 g

mass=?

m=h/mv

Calculate the wavelength of a baseball (m = 155 g) moving at 32.5 m/s.

λ ≈ h / (mv) = (6.626x10^-34 kg m²/s) / (0.155kg x 32.5 m/s) = 1.32x10^-34 m/s

What are the possible values of n and ml for an electron in a 5 p orbital?

n = 5 and ml = -1, 0, +1

In which orbital below would an electron (on average) be closest to the nucleus?

2s

Each of the following sets of quantum numbers is supposed to specify an orbital. Choose the one set of quantum numbers that does NOT contain an error.

Each of the following sets of quantum numbers is supposed to specify an orbital. Choose the one set of quantum numbers that does NOT contain an error.

n = 3, l = 2, ml =-3

n = 4, l = 3, ml =-2

n = 2, l = 2, ml =-1

n = 2, l = -1, ml =0

n = 4, l = 2, ml =+4

n = 4, l = 3, ml =-2

Which of the following quantum numbers describes the size and energy of an orbital?

principal quantum number

What is the maximum number of s orbitals that are possible in a given shell?

1

Choose the transition (in a hydrogen atom) below that represents the absorption of the shortest wavelength photon.

Choose the transition (in a hydrogen atom) below that represents the absorption of the shortest wavelength photon.

n = 4 to n = 6

n = 2 to n = 3

n = 1 to n = 2

n = 3 to n = 1

n = 6 to n = 5

n = 1 to n = 2

What values of l are possible for n=4?

0, 1, 2, and 3 (or s, p, d, and f)

What is l max value?

l has a maximum value of n-1

Calculate the frequency of light associated with the transition from n = 2 to n = 3 in the hydrogen atom.

Rydberg wavelength equation:

1/λ = RH * [(1 / n²i) - (1 / n²f)]

RH = Rydberg constant = (1.097 x 10^7 / m)

ni = initial energy level

nf = final energy level

In this case, ni = 2 and nf = 3. Use the Rydberg equation to find the wavelength λ and then use f = (c/λ) to find the frequency.

1/λ = (1.097 x 10^7 / m) * [(1 / 2²) - (1 / 3²)]

1/λ = (1.097 x 10^7 / m) * [(1/4) - (1/9)]

1/λ = 1.524 x 10^6 / m

λ = [1 / (1.524 x 10^6 / m)]

λ = 6.563 X 10^-7 m

c = speed of light = 2.998 x 10^8 m/s

Find frequency using f = (c/λ):

f = [(2.998 x 10^8 m/s) / (6.563 x 10^-7 m)] = 4.57 x 10^14 s⁻¹

Rydberg wavelength equation

1/λ = RH * [(1 / n²i) - (1 / n²f)]

RH = Rydberg constant = (1.097 x 10^7 / m)

ni = initial energy level

nf = final energy level

Denisty

mass/volume

extensive properties

dependent on the amount of substance present

intensive property

independent of the amount of substance present

Chemisty

is the science that seeks to understand the properties of matter by studing the structure of the paticles that compose it

matter

Anything that has mass and takes up space

solids

Definite shape and volume

liquid

definite volume, indefinite shape

gases

No definite shape or volume

pure substance

are made up of only one type of particle

element

cannot be broken down chemically into simple sustance

compounds

combination of elements

mixture

a substance composed of two or more particles in proportion that can vary from sample to sample

homogenous mixture

have the same properties through out the sample

heterogenous mixture

have different properties throughout the mixture

Hypothesis

tenative explaination

Law of conservation of Matter

in a chemical reaction, atoms can be neither created nor destroyed, only rearranged

A LAW

summary of observed behavior

a theroy

is a model that bot only explains what nature dies but why it does what it does

law of definite proportions

all samples of a given compound, regardless of their source or how they were prepared, have the same proportions of their constituent elements

Law of Multiple Proportions

when two elements combine with each other to form more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.

radioactivity

the process in which an unstable atomic nucleus emits charged particles and energy

protons and nuetrons

1.67*10^-27

electrons

.00091*10^-27

Which weighs more a Hydrogen atom or Helium atom

Helium weighs four times more than hydrogen because it has two protons

atomic number

the number of protons in the nucleus of an atom

isotopes

Atoms with the same number of protons but different numbers of neutrons

mass number of an atom

the sum of its protons and neutrons in the nucleus

cations

Atoms with a positive charge

anion

atom with a negative charge

light

electromatic wave

magnetic field

is a region in space where a magnet experiences a force

wave length and units

landa is the distance between corresponding points in a wave

distance

different wavelengths are different colors

frequency

v is the number of wave creast that pass a point in one second unit R^-1

speed of a wave=

landa *v or(wavelength * frequency)

for electromagnetic equation

c= landa * V (wavelength * frequency)

c= speed of light = 3*10^8

What is the binding energy of the electron in kJ/mol? [Note that KE = 12mv2 and 1 electron volt (eV) = 1.602×10−19J.]

The binding energy, BE, is the difference between the energy of the incident photon, Ephoton, and the kinetic energy of the emitted electron, KEelectron. Calculate the binding energy of the electron using

BE=Ephoton−KEelectron

where

Ephoton=hcλ

where h is Planck's constant (h=6.626×10−34J⋅s) and c the speed of light (c=3.00×108m/s). Convert the kinetic energy to J and finally convert the difference to kJ/mol. The calculation can be summarized as follows:

BE=[(6.626×10−34J⋅s)(3.00×108m/s)

/0.948 nm×10−9m/nm)

−(994 eV)(1.602×10−19J/eV)]

×1kJ/1000J×6.022×10^23/mol