Che 2a: Midterm 1 - Hayashi

Law Of Conservation of mass

(total mass of reactants)=(total mass of products)

Mass is conservced during any chemical reaction (not applicable to nuclear atoms)

law of definite proportions

all samples of the same compound have the same composition the same proportions by mass of the constituent elements

What are the small particles that make up each element?

Atoms

According to Dalton's Atomic Theory, can atoms be created or destroyed?

No, atoms are neither created nor destroyed.

What is true about all atoms of a given element according to Dalton's Atomic Theory?

All atoms of a given element are identical in mass and other properties.

How do atoms of one element differ from atoms of another element?

Atoms of one element differ from all other elements.

Law of multiple proportions

Compounds are formed when atoms of more than one element combine in whole number ratios

Law of Combining volumes ( 1809)

when gasses chemically react they do in volumes that are always in simple whole number ratios

Avogadros interpretation:

2H+ 1O -> 2 water molecule

Cathode tube ray

Vaccum tube containing an electron gun and a flourescent screen to detect the position of the cathode ray

Thomsons Cathode ray tube experiment (1897)

Thomson calc value of mass to charge ratio m /e of an electron by conducting the cathode ray tube experimnent a cathode ray tube is a vaccum tibe containing an electron gun

electron m/e= -5.6857 x 10^-9 g/ coloumb

Milikans oil drop experiment

Changed oil droplets accelerate due to the electric field

- milikan concluded that the magnitude of the charge on a droplet is an integer multople of the electric charge e

e = 1.602 x 10^-19C (elementary charge)

Who proposed the plum pudding model?

JJ Thompson

In the plum pudding model, what do the electrons represent?

Plums

In the plum pudding model, what does the positive charge represent?

Pudding

What is the main idea of the plum pudding model?

Electrons are surrounded by a positively charged cloud to balance their negative charge.

What was the Rutherford gold foil experiment?

An experiment where a beam of alpha particles was directed onto a sheet of thin gold foil.

What type of particles were used in the Rutherford gold foil experiment?

Alpha particles (He^2+).

What was the purpose of the evacuated chamber in the Rutherford gold foil experiment?

To prevent interference from air particles.

What was observed when alpha particles were directed at the gold foil?

Particles were deflected at various angles.

What did the detection of deflected particles in the Rutherford gold foil experiment indicate?

It indicated the presence of a small, dense nucleus in the atom.

Nuclear Atom

Most of the mass and all of the positive charge is concentrated in a small region referred to as the nucleus

compensating charge of electrons outside of the nucleus

What is the nucleus of an atom made of?

Protons and neutrons

How do the masses of protons and neutrons compare?

They are almost the same

What is the mass of an electron compared to a proton or neutron?

About 1/1800 times the mass of a proton or neutron

What is the atomic number?

The atomic number is the number of protons in an atom.

What does the atomic number equal in a neutral atom?

In a neutral atom, the atomic number is equal to the number of electrons.

What is the mass number?

The mass number is the number of protons plus the number of neutrons.

How is the mass number calculated?

The mass number (A) is calculated as A = p + n, where p is the number of protons and n is the number of neutrons.

Isotopic Mass

Mass of a specific atom

Atomic mass unit AMU

used to measure the isotopic mass

1 AMU+ 1/12 carbon 12

1 u = 1/12 x (mass of the 12 6 C atom)

Mass spectroscopy

used to est isotopic masses and percent natural abundance of isotoped of an element

Atomic Mass

Average of the isotopic masses, weihgted accoprding to the naturally occuring abundance of the isotopes of the element

Atomic mass of an element

(fractional abundance of isotope 1 x Isotopic mass of isotope 1 ) + (fractional abundance of isoptope 2 x isotopic mass of isotope 2 ) + ...

Periodic table groups

Alkali metals -1

Alkaline earths- 2

Transition Metals- 3-12

Halogens - 17

Noble gasses- 18

Molecular Compounds

Made of discrete units called molecules

each molecule consits of a certain number of non metal atoms held together by stron covalent bonds

What is an empirical formula?

The simplest whole number ratio of atoms of each element in a compound.

What is a molecular formula?

The actual molecule of an element or compound.

What does a structural formula provide?

The same information as a molecular formula but also shows the connectivity of atoms.

What are the two types of molecular models?

Space-filling models and ball-and-stick models.

What is an extended structural formula?

A structural formula that shows the connectivity of all atoms explicitly.

What is a condensed structural formula?

A structural formula that shows the connectivity of atoms in less detail.

What is a line angle formula?

A simplified structural formula of an organic compound that does not show the C and H atoms explicitly.

What are ions?

Charged species formed when atoms gain or lose electrons.

What do metals tend to do with electrons?

Metals tend to lose electrons to form positively charged ions called cations.

What do non-metals tend to do with electrons?

Non-metals tend to gain electrons to form negatively charged ions called anions.

Formula unit

Smallest electrically nuetral connection of ions

Oxidation state

hypothetical chgargfe of an atom if all the shared electrons in its covalent bonds were assigned to the more electro negative atoms

What is the oxidation state of an individual atom in a free element?

0

What is the total oxidation state of all atoms in a neutral species?

0

What is the total oxidation state of all atoms in an ion?

The total charge on the ion

What is the oxidation state of a Group 1 metal in a compound?

+1

What is the oxidation state of a Group 2 metal in a compound?

+2

What is the oxidation state of fluorine in its compounds?

-1

What is the oxidation state of hydrogen in its compounds?

+1

What is the oxidation state of oxygen in its compounds?

-2

What is the oxidation state of halogens (Group 17) in binary compounds with metals?

-1

What is the oxidation state of halogens (Group 16) in binary compounds with metals?

-2

What is the oxidation state of halogens (Group 15) in binary compounds with metals?

-3

Alkali, Alkaline earth, Transition, Metalloids, Halogens, Noble gasses, Lanthanides, Actinides

Which is named first nonmetal or metal?

Metal is named first and then nonmetal

How does the metal element change?

The metal element doesn't change it remains the same

What ending does a nonmetal take?

Nonmetal element Becomes "-ide"

NaCl

Sodium Chloride

MgI2

Magenesium iodide

Al2O3

Aluminum oxide

What are the charges of Monatomic Ions?

Groups 1,2 :

1= +1

2=+2

Groups 7-12: +2 (variable)

Group 13: 3+

Group 14: +4

Group 15: -3

Group 16: -2

Group 17: -1

Name these Ions:

Fe +2, +3

Cu +1, +2

Au +1, +3

Hg +1(Hg2 2+), +2

Sn +2, +4

Pb +2, +4

Iron (II), Iron (III)

Copper (I), Copper (II)

Gold (I), Gold (III)

Mercury (I), Mercury (II)

Tin (II), Tin (IV)

Lead (II), Lead (IV)

Name these Ions: Alternate

Fe +2, +3

Cu +1, +2

Au +1, +3

Hg +1(Hg2 2+), +2

Sn +2, +4

Pb +2, +4

Ferrous, Ferric

Cuprous, Cupric

Aurous, Auric

Mercurous, Mercuric

Stannous, Stannic

Plumbous, Plumbic

Which O.S element is first (pos or neg)

( 2 nonmetals)

The positive O.S element is named first

What is the name of the first element in the formula ( 2 nonmetals)

the same

What does the second element end in ( 2 nonmetals)

- Ide

What is used to denote the number of atoms of each element?( 2 nonmetals )

Prefixes

Which prefix is never used? ( 2 nonmetals)

Mono (1)

Prefixes:

mono

di

tri

tetra

penta

heaxa

octa

nona

deca

1

2

3

4

5

6

7

8

9

10

When the prefix ends in "a" or "o" the element name begins with?

"a" or "o"

the final vowel of the prefix dropped

BCl3 Boron trichloride

CCl4 Carbon tertrachloride

CO Carbon monoxide

NO Nitrogen monoxide

Name these compounds?

NO2

N2O

N2O3

N2O4

N2O5

PCl3

PCl5

SF6

Nitrogen dioxide

Dinitrogen monoxide

Dinitrogen trioxide

Dinitrogen tetroxide

Dinitrogen pentoxide

Phosphorous trichloride

Phosphorous pentachloride

Sulfur hexafluoride

Binary acids dissolved in water are named with the prefix "***-" and suffix "-*"

prefix "hydro-" and suffix "-ic"

Name these binary acides

HF(aq)

HCl ( aq)

HBr (aq)

HI(aq)

H2S (aq)

hydrofluoric acid

hydrochloric acid

hydrobromic acids

hydroiodic acid

hydrosulfuric acid

What forms a polyatomnic ion?

2 or more atoms joint by covalent bonds

What are Oxoanions ?

polyatomixc anions containing oxygen in combination with another nonmetal

Which oxoanions form a series of oxoanions contains different numbers oxygen atoms, what are their names related to?

Cl, N, P, S

Their names are related to the oxidation states of the nonmetal atoms to which O atoms are bonded.

What does increasing the oxidation state of a nonmetal do? ( us ClO as an ex ClO-, ClO -2, ClO-3, Clo-4)

Increases the number of O atoms

Hypo __ ite

__ite

___ate

per____ ate

hypochlorate,

chlorite

chlorate

perchlorate

NH4+

Ammonium ion

CH3COO-

Acetate ion

CO3 2-

Carbonate ion

HCO3 -

Hydrogen carbonate

or Bicarbonate

ClO-

Hypochlorite

ClO2-

Chlorite ion

ClO3-

Chlorate ion

ClO4-

Perchlorate ion

CrO4 2-

Chromate ion

Cr2O7 2-

Dichromate ion

CN-

Cyanide ion

OH-

Hydroxide ion

NO2-

Nitrite ion

NO3-

Nitrate ion

C2O4 2-

Oxalate ion

MnO4

Permaganate ion

PO4 3-

Phospate ion