Shared Flashcard Set

Details

Chapter 2 notes
ch 2 (chem 1)
96
Chemistry
Undergraduate 1
02/09/2010

Additional Chemistry Flashcards

 


 

Cards

Term

atomic number

 

 

 

AZX

Definition

# protons in nucleus

 

 

 

ZX

Term

mass number

 

 

 

AZX

Definition

# protons + # neutrons

 

 

 

AX

Term
what is the number of protons, neutrons, and electrons for 6329Cu
Definition

p = 29

n = 63 - 29= 34                      

e = 29

Term
how many prtons, enutrons, and electrons are in (a) Gold-197 (b) Strontium-90?
Definition

(a) 19779Au

p = 79

n = 197 - 79=118                   

e = 79

 

(b) 9038Sr

p = 38

n = 90 - 38=52                       

e = 38

Term
isotope
Definition
atoms of the same element (X) with different numbers of neutrons in their nuclei
Term

hydrogen has 3 isotopes:

11H,   21H (Duterium),   31H (Tritium)

what are the protons, neutrons, and electrons of each?

Definition

11H : p = 1

n = 1 - 1=                      

e =                               

                             

21H : p = 1

n = 2 - 1=                      

e =                               

                              

31H : p = 1

n = 3 - 1=                      

e = 1                               

Term

Uranium has 2 isotopes:

23592U,   23892U

what are the protons, neutrons, and electrons?

Definition

23592U : p = 92

n = 235 - 92=143             

e = 92                            

 

23892U : p =92

n = 238 - 92=146            

e = 92                           

Term
Silver occurs as 2 isotopes, 107Ag and 109Ag. Silver-107 has a mass of 106.90509amu and a percentage abundance of 51.84%. Silver-109 has a mass of 108.90476amu and a percentage abundance of 48.16%. What is the average atomic weight of silver?
Definition

atomic weight = ∑ [(%abundance/100) X (mass of isotope)]

(0.5184 X 106.90509amu) + (.4816 X 108.90476) = 107.9amu

Term
Lithium has 2 occuring isotopes, 6Li and 7Li, with masses of 6.0151amu and 7.0160amu, respectively. Calculate the percent abundance of these isotopes of Lithium.
Definition

6Li = x     7Li = (1 - x)

Li = 6.941amu

6.941amu = (x)(6.0151amu) + (1 - x)(7.0160amu)

6.941amu = 6.0151x + 7.0160 + 7.0160x

   1.0009x = 7.0160 - 6.941

   1.0009x = .075

            x = 0.075

 

6Li = 7.5%

7Li = 92.5%

Term
what is a compound?
Definition
a combination of 2 or more elements in definite ratios by mass. The character of each element is lost when forming a compound.
Term
what is a molecule?
Definition
an aggregate of 2 or more atoms in a definite arrangement held together by chemical forces
Term
what is a diatomic molecule?
Definition
only contains 2 atoms
Term
elements that exist as diatomic molecules are?
Definition
H2, F2, Cl2, Br2, I2, O2, N2
Term
what is a polyatomic molecule?
Definition
contains more than 2 atoms
Term
elements that exist as polyatomic molecules are
Definition
O3, S8
Term
what is an ion?
Definition
an atom, or group of atoms, that has a net positive or negative charge
Term
what is a cation?
Definition

ion with a positive charge (metals that lose electrons)

 

Ex: Na -- -e- --> Na+

    (11p, 11e)    (11p, 10e)

Term
what is an anion?
Definition

ion with a negative charge (nonmetals gain electrons)

 

Ex: F -- +e- --> F-

       (9p, 9e)      (9p, 10e)

Term
what is a monotomic ion?
Definition
contains only one atom
Term
what is a polyatomic ion?
Definition
contains more than one atom
Term
how many protons and electrons are in 2713Al3+?
Definition

p = 13

          e = 13 - 3=10

Term
how many protons and electrons are in 7834Se2-?
Definition

p = 34

           e = 34 + 2=36

Term
what is a molecular formula?
Definition

shows the exact number of atoms of each element in the smallest unit of a substance

 

 

Ex: H2O

     C6H12O6

     O3

     N2H4

Term
what is an empirical formula?
Definition

shows the simplest whole-number ratio of the atoms in a substance

 

Ex: H2O

     CH2O

     O

     NH2

Term
what is an ionic compound?
Definition
consists of a combination of cations and anions
Term
formulas of ionic compounds
Definition

1. ionic compounds consist of a combination of cations and anions

 

2. the formula is always the same as the empirical formula

 

3. the sum of the charges on the cation(s) and anion(s) in each formula unit must equal zero

 

 

Ex: the ionic compound of NaCl = Na+ Cl-

Term

predicting charges on cations

(a) metals of the main group elements (A groups) and H form cations whose (+) charge is equal to the group number

 

(b) some metals form cations with more than one charge (usually transition metals)

Definition

(a) Group I A = (H+), Li+, Na+, K+, Rb+, Cs+

     Group II A = Be2+, Hg2+, Ca2+, Sr2+, Ba2+

      Group III A = Al3+, Ga3+

(b) Fe2+, Cu+, Cr2+, Co2+

     Fe3+, Cu2+, Cr3+, Co3+

exception which are not transition metals: Sn2+, Pb2+

                                                           Sn4+, Pb4+

Term

predicting charges on anions

 

(a) nonmetals of the main group elements form anions whose negative charge equals the group # minus 8

 

(b) polyatomic anions

Definition

(a) Group V A = N3-, P3-

     Group VI A = O2-, S2-

     Group VII A = F-, Cl-, Br-, I-

Term

writing formulas of ionic compounds

 

in an ionic compound, the anions and cations exist together in a ration such that the (-) charge balances the (+) charge

Definition

Mg2+ F- = MgF2   

Al3+ O2- = Al2O3   

Na+ SO42- = Na2SO4   

Ca2+ PO43- = Ca3(PO4)2

Term

naming cations

(a) monatomic cations are named after the element

 

(b) if the metal can form more than one cation, indicate the (+) charge with Roman Numerals

 

(c) polyatomic cations end in -ium

Definition

(a) Li+ = Lithium

     Mg2+ = Magnesium

 

(b) Cu+ = Copper I

     Cu2+ = Copper II

 

(c) NH4+ = ammonium

Term
N3-
Definition
nitride
Term
P3-
Definition
phosphide
Term
O2-
Definition
oxide
Term
S2-
Definition
sulfide
Term
Se2-
Definition
selenide
Term
Te2-
Definition
telluride
Term
F-
Definition
flouride
Term
Cl-
Definition
chloride
Term
Br-
Definition
bromide
Term
I-
Definition
iodide
Term
NH4+
Definition
ammonium
Term
CN-
Definition
cyanide
Term
CH3CO2-
Definition
acetate
Term
CO32-
Definition
carbonate
Term
HCO3-
Definition
hydrogen carbonate/bicarbonate
Term
NO2-
Definition
nitrite
Term
NO3-
Definition
nitrate
Term
PO43-
Definition
phosphate
Term
HPO42-
Definition
hydrogen phosphate
Term
H2PO4-
Definition
dihydrogen phosphate
Term
OH-
Definition
hydroxide
Term
SO32-
Definition
sulfite
Term
SO42-
Definition
sulfate
Term
HSO4-
Definition
hydrogen sulfate/bisulfate
Term
ClO-
Definition
hypochlorite
Term
ClO2-
Definition
chlorite
Term
ClO3-
Definition
chlorate
Term
ClO4-
Definition
perchlorate
Term
CrO42-
Definition
chromate
Term
Cr2O72-
Definition
dichromate
Term
MnO4-
Definition
permanganate
Term
O22-
Definition
peroxide
Term
naming ionic compounds whose cation forms only one charge
Definition

rule: name the matal cation first, followed by the non-metal anion.

 

Na+ Cl- = NaCl = sodium chloride

K+ CN- = KCN = potassium cyanide

Na+ SO42- = Na2SO4 = sodium sulfate

Mg2+ N3- = Mg3N2 = magnesium nitride

Mg2+ PO43- = Mg3(PO4)2 = magnesium phosphate

K+ CO32- = K2CO3 = potassium carbonate

Na+ O22- = Na2O2 = sodium peroxide

Term
naming ionic compounds whose cation forms more than one charge - known as the  stock system
Definition

rule: (a) write the name of the cation

       (b) write the charge on the cation as a roman numeral

       (c) write the name of the anion

 

FeCl2 = Fe2+ Cl- = Iron II Chloride

Cu2O = Cu+ O2- = Copper I Oxide

Cr2O3 = Cr3+ O2- = Chromium III Oxide

SnO2 = Sn4+ O2- = Tin IV Oxide

PbI2 = Pb2+I- = Lead II Iodide

Term
naming molecular compounds
Definition

rule: (a) name the first element and add -ide to the stem of the name of the second element

       (b) indicate the number of each element by the use of Greek prefixes

 

N2O3 = dinitrogen trioxide

P4S3 = tetraphosphorous trisulfide

CO2 = carbon dioxide

CO = carbon monoxide

PCl5 = phosphorous pentachloride

SF6 = sulfur hexafluoride

Cl2O7 = dochlorine heptoxide

CCl4 = carbon tetrachloride

Term
1
Definition
mono
Term
2
Definition
di
Term
3
Definition
tri
Term
4
Definition
tetra
Term
5
Definition
penta
Term
6
Definition
hexa
Term
7
Definition
hepta
Term
8
Definition
octa
Term
9
Definition
nona
Term
10
Definition
deca
Term
what are hydrates?
Definition

compounds that have a specific number of water molecules attatched to them

 

BaCl2 • 2H2O = barium chloride dihydrate

LiCl • H2O = litium chloride monohydrate

MgSO4 • 7H2O = magnesium sulfate heptahydrate

Sr(NO3)2 • 4H2O = strontium nitrate tetrahydrate

Term

give the formula names for the following ionic compounds

(a) ammonium nitrate

(b) colbalt (II) sulfate

(c) barium acetate

(d) vanadium (III) oxide

(e) KMnO4

(f) Li2CO3

(g) CuCl2

Definition

(a) NH4NO3 (NH4+ NO3-)

(b) CoSO4 (Co2+ SO42-)

(c) Ba(CH3CO2)2 (Ba2+ CH3CO2-)

(d) V2O3 (V3+ O2-)

(f) lithium carbonate

(g) copper (II) chloride

Term

give the formula and the name of the following molecular compounds

(a) carbon dioxide

(b) phosphorous triiodide

(c) sulfur dichloride

(d) P4O10

(e) SF4

(f) N2F4

Definition

(a) CO2

(b) PI3

(c) SCl2

(d) tetraphosphorous decaoxide

(e) sulfur tetraflouride

(f) dinitrogen tetraflouride

Term
avagadro's number/mole
Definition
6.022 X 1023
Term
molar mass
Definition

the mass of 1 mole of a substance in grams

 

(M = molar mass in g/mol     NA = Avagadro's number)

g --m/M--> mol --nNA--> # atoms

g <--nM-- mol <--N/NA-- # atoms

Term
how many moles of magnesium are there in 87.3g of Mg?
Definition

g-->mol

mass(g) X 1mol/molar mass(g) = mol

87.3g Mg X 1mol Mg/24.30g = 3.59mol

Term
how many atoms of potassium are in 0.551g of potassium?
Definition

g-->mol-->atoms

0.551g K X (1mol K/39.10g K) X (6.022 X 1023atom K/1mol K) = 8.49 X 1021atoms K

Term
what is molecular mass?
Definition

the sum of the atomic masses (amu) in a molecule

 

SO2:

1 S = 32.07amu    +

2 O = 2 X 16.00amu

= 64.07amu   

Term
what is formula mass?
Definition

the sum of the atomic masses (amu) in a formula unit of an ionic compound

NaCl:

1 Na = 22.99amu   

1 Cl = 35.45amu +

= 58.44amu 

Term
what is the mass in grams of 3.25mol of glucose, C6H12O6?
Definition

(C6H12O6 = 180.0g/mol)

mol --> g

3.25mol C6H12O6 X (180.0g/1mol C6H12O6) = 585g C6H12O6

Term
calculate the number of moles of CHCl3 in 198g of CHCl3?
Definition

(CHCl3 = 1119.5g/mol)

g --> mol

198g CHCl3 X (1mol CHCl3/119.5g CHCl3) = 1.66mol CHCl3

Term
how many molecules of HCl are in 3.46g of HCl?
Definition

(HCl = 36.5g/mol)

g --> mol --> molecules

3.46g HCl X (1mol HCl/36.5g) X (6.022 X 1023 molec HCl/1mol HCl) = 5.71 X 1022 HCl molec

Term
how many H atoms are in 72.5g of C3H8O?
Definition

(C3H8O = 60.0g/mol)

g --> mol --> molecules --> atoms

72.5g C3H8O X (1mol C3H8O/60.0g C3H8O) X (6.022 X 1023 molec C3H8O/1mol C3H8O) X (8 atom H/1molec C3H8O) = 5.82 X 1024 atoms H

Term
mass percent of an element in a compound
Definition
(n X molar mass of element/molar mass of compound) X 100
Term
what is the mass percent of C2H6O for each C2, H6, and O?
Definition

(C2H6O = 46.07g/mol)

%C = [(2 X 12.01g)/46.07g] X 100 = 52.14% C

%H = [(6 X 1.008g)/46.07g] X 100 = 13.13% H

%O = [(1 X 16.00g)/46.07g] X 100 = 34.73% O

Term
what is the mass percent of each element in glucose, C6H12O6?
Definition

(C6H12O6 = 180.0g/mol)

%C = 40.04%

%H = 6.72% +

%O = 53.33% +

 = 100%

Term
what is the mass of carbon in 61.8g of sucrose, C12H22O11?
Definition

(C12H22O11 = 342.3g/mol)

%C = [(12 X 12.01g)/342.3g] X 100 = 42% C

61.8g X 0.42 = 26.0g C

Term
determine the empirical formula of a compound that has the following percent composition by mass: H 2.1%, O 65.3%, S 32.6%?
Definition

2.1g H X (1mol H/1.008g) = 2.08mol/1.02 = 2

32.6g S X (1mol S/32.0g S) = 1.02mol/1.02 = 1

65.3g O X (1mol O/16.0g O) = 4.08/1.02 = 4

 

H2SO4

Term
adipic acid contains 49.32% C, 43.84% O, and 6.85% H by mass. What is the empirical formula of adipic acid?
Definition

49.32g C X (1mol C/12.01g C) = 4.107mol/2.74 = 1.5

43.84g O X (1mol O/16.00g O) = 2.74/2.74 = 1

6.85g H X (1mol H/1.008g H) = 6.796mol/2.74 = 2.5

C3H5O2

DO NOT ROUND SUBSCRIPTS!!!

Term
caffine has a molar mass of 194.19g/mol and a mass composition of 49.48% C, 5.19% H, 28.85% N, and 16.48% O. Whiat is the molecular formula of caffeine?
Definition

49.48g C X (1mol C/12.01g C) = 4.12mol/1.03 = 4

5.19g H X (1mol H/1.008g H) = 5.15mol/1.03 = 5

28.85g N X (1mol N/14.01g N) = 2.06mol/1.03 = 2

16.48g O X (1mol O/16.0g O) = 1.03mol/1.03 = 1

 

Empirical = C4H5N2O

integral factor = (194.19/97.1) = 2

Molecular=

C8H10N4O2

Term
gallium oxide, GaxOy, forms when gallium is combined with oxygen. Suppose you allow 1.25g of gallium (Ga) to react with oxygen and obtain 1.68g of GaxOy. What is the formula of the product?
Definition

amount of oxygen = 1.68g - 1.25g = 0.43g

1.25g Ga X (1mol Ga/69.72g Ga) = .0179mol/.0179 = 1

0.43g O X (1mol O/16.00g O) = .0269mol/.0179 = 1.5

Ga2O3

Supporting users have an ad free experience!