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Chemistry Exam 1
Covering Chapters 1,2 & 3
62
Chemistry
Undergraduate 1
09/11/2010

Additional Chemistry Flashcards

 


 

Cards

Term
How to calculate an average atomic mass?
Definition

example:

98.93 % 12^c & 1.07% 13^C  masses are 12 amu, and 13.00335.

 

(0.9893)(12amu) + (0.0107)(13.00335amu) = 12.01amu

a.k.a Atomic Weight

Term
How much does 1 amu = ?
Definition
1.66054 x 10-24
Term
What is Avogadro's Number?
Definition
6.0221421 x 1023
Term
[image]
Definition
[image]
Term

Significant Figures:

 

Addition and Subtraction

the result has the ____ number of decimal places as the measurment with the ______ decimal places.

Definition
Same number of decinmal places as the measurment with the Fewest decimal places
Term
7 Diatomic Molecules
Definition
H,N,O,F,Cl,Br,I
Term

How to calculate mass number

 

ex: 12C

Definition
Number of Protons + Neutrons
Term

How to calculate Atomic number

 

ex. 6C

Definition
Number of Protons or Electrons
Term
What is an Isotope?
Definition
Same number of protons but different numbers of neutrons.
Term
What subatomic particle defines an element?
Definition
Proton
Term
Name the three types of radiation.
Definition
aAlpha      bBeta     gGamma 
Term
Which 2 types of radiation are bent by an electric field>
Definition
Both aAlpha+ and bBeta-
Term
What is Dalton's 1st postulate?
Definition
Each element is composed of extremely small particles called atoms.
Term
What is Dalton's 2nd postulate?
Definition
All atoms of a given element are identicle to one another in mass and other properties, but the atoms of one element are different from the atoms of all other elements.
Term
What is Dalton's 3rd Postulate?
Definition
The atoms of one element cannot be changed into atoms of a different element by chemical reactions; atoms are neither created nor destroyed in chemical reactions.
Term
What is Dalton's 4th postulate?
Definition
Compounds are formed when atoms of more than one element combine; a given compound always has the same relative number and kind of atoms.
Term
What law can we conclude from Dalton's 4th Postulate?
Definition
The law of constant composition
Term
What is the law of costant composition?
Definition
In a given compound, the relative numbers and kinds of atoms are constant.
Term
What law can we conclude from Dalton's 3rd postulate?
Definition
Low of conservation of mass a.k.a. law of conservation of matter
Term
What is the law of conservation of mass/matter?
Definition
The total mass of materials present after a chemical reaction is the same as the total mass present before the reaction.
Term
Law of Multiple proportions
Definition

 It states that the masses of one element which combine with a fixed mass of the second element are in a ratio of whole numbers

postulate 3

Term
What is the formula to calculate oF to oC
Definition
oC = 5/9 (oF -32)
Term
What is the formula to convert oC to oF?
Definition
oF=9/5 (oC) +32
Term

Rule #1 of significant figures

 

Zeros between nonzero digits

Definition

Always important

ex. 1005 4 sig figs

ex. 1.03 3 sig figs

Term

Rule # 2 signifigant figures

 

Zeros at the beginning of a number

Definition

NEVER significant

 

(merley indicate the position of the decimal point)

 

ex. 0.02 one significant figure

Term

Rule #3 of significant figures

 

Zeros at the end of a number

Definition

Are significant if the number contains a decimal point

ex. 0.0200 3 significant figures

ex. 3.0 2 significant figures     

Term

Significant figures:

 

In any measurment that is poroperly reported, all nonzero digits are ____

Definition
Significant
Term
How do you get the Formula Weight?
Definition

The sum of the atomic weights of each atom in it's chemical formula.

 

ex.12 C atoms = 12(12.0amu) = 144.0amu       

22 H atoms = 22(1.0) = 22.0amu            

11 O atoms = 11(16.0 amu) = 176.0 amu


Total: 342.0 amu (Formula Weight)

Term
What is a molecule?
Definition
2 Or more atoms are joined together in specific shapes
Term
Pure substance
Definition
Distinct properties and a composition that does not very from sample to sample.
Term
Intensive properties
Definition

Temperatue, melting point, and density

(do not depend on quantity)

Term
Extensive properties
Definition

(depend on the quantity of the sample)

 

mass and volume

Term
What is a chemical reaction?
Definition
Substance transforming into a chemically different substance.
Term
How do you calculate Molecular Weight?
Definition

If the chemical formula is that of that of a molecule, then the formula weight is also called the moecular weight.

 

ex. glucose C6H12O6

MW :6(12.0amu)+12(1.0amu)+6(16.0amu)=180amu

Term

Percent Composition from Formulas

 

Definition

%element =

 

 (Number of atoms of that element) (atomic weight of element)

 


 

Formula weight of compound

 

x 100%

Term

Estimating Numbers of Atoms

 

Ex. Without using a calculator, arrange the following samples in order of increaasing numbers of carbon atoms:12g 12C, 1 mol C2H2, 9 x 1023 molecules of CO2.

Definition

1. Analyze- We are given amounts of different substances expressed in grams, moles, and a number of molecules and asked to arrange the samples in order of increasing numbers of C atoms.

 

2. Plan- To determine the number of C atoms in each sample, we must convert g 12C,1 mol C2H3 and 9 x 1023 molecules CO2 all to numbers of C atoms. To make these conversions, we use the definition of mole and Avogadro's number.

 

3. Solve- A mole is defined as the amount of matter that contains as many units of the matter as there are C atoms in exactly 12 g of 12C. Thus, 12g of 12C contains 1 mol of C atoms (that is 6.02 x 1023 atoms). One mol of C2H2 molecule, this sample contains 12 x 1023 C atoms. Because each CO2 molecule contains one C atom, the sample of CO2 contains one C atom, the CO2 contains

 

 

Term
Ammonium Ion
Definition
NH4+
Term
Copper(I) or Cuprous ion
Definition
Cu+
Term
Cobalt(II)
Definition
Co2+
Term
Iron(II) or ferrous ion
Definition
Fe2+
Term
Mercury(I) or mer-curous ion
Definition
Hg22+
Term
Lead(II) or plumbous ion
Definition
Pb2+
Term
Manganese(II) or manganous ion
Definition
Mn2+
Term
Tin(II) or stannous ion
Definition
Sn2+
Term
Mercury(II) Mercuric ion
Definition
Hg2+
Term
Nickel(II) or nickelous
Definition
Ni2+
Term
Chromium(III) or chromic ion
Definition
Cr3+
Term
Iron(III) or Ferric ion
Definition
Fe3+
Term
Hydrogen Ion
Definition
H+
Term
Lithium Ion
Definition
Li+
Term
Sodium Ion
Definition
Na+
Term
Potassium Ion
Definition
K+
Term
Cesium
Definition
Cs+
Term
Silver Ion
Definition
Ag+
Term
Magnesium Ion
Definition
Term
Calcium Ion
Definition
Ca2+
Term
Stronium Ion
Definition
Sr2+
Term
Barium ion
Definition
Ba2+
Term
Definition
Zn2+
Term
Cadmium ion
Definition
Cd2+
Term
Aluminum Ion
Definition
Al3+
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