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Chemistry flashcards
Comps 7th grade
91
Chemistry
7th Grade
01/12/2013

Additional Chemistry Flashcards

 


 

Cards

Term
Who devised the theory of the atom?
Definition
Democratis
Term
Atomic number
Definition
The number of protons in the nucleus
Term
Atomic mass
Definition
The average weight of the element
Term
Mass number
Definition
The rounded atomic mass, the number of protons and neutrons
Term
Nucleus
Definition
Positively charged center of the atom, contains protons and neutrons
Term
Protons
Definition
Positive particle, in the nucleus
Term
Neutrons
Definition
No charge, in nucleus
Term
Electrons
Definition
Negative, orbit around nucleus
Term
Ion
Definition
Atom with a positive or negative charge
Term
Draw an example of a shorthand notation
Definition

Look at notes 


Term
A neutral atom has ______ number of electrons and protons
Definition
An equal
Term
Isotope
Definition
Variety of the same element all with different masses
Term

Find the electron configuration of Calcium

(use your tables)

Definition
1s22s22p63s23p64s2
Term
How many valence electrons does Nitrogen have?
Definition
5
Term

What is the charge of the Alikali Metals?

Why?

Definition
+1; because it gives up 1 electron to get 8 valence electrons
Term

Nonmetals __________ to get 8 valence electrons

Metals __________ to get 8 valence electrons

Definition
Steal electrons; give electrons
Term
Period
Definition
Horizontal rows
Term
Group
Definition
Vertical families
Term
What charge do the Alkaline earth metals have?
Definition
+2
Term
What family is the least reactive?
Definition
The Noble gases
Term

What charge does the Halogens family have?

Why?

Definition
-1;because it steals 1 electron to get 8 valence electrons
Term
Nonmetals steal electrons from _______
Definition
Metals
Term
Do nonmetals or metals have a higher ionization energy?
Definition
Nonmetals
Term
What is ionization energy?
Definition
The energey required to remove an electron from an atom
Term
Atomic radius
Definition
deals with the size
Term
Electron affinity
Definition
Ability of an element to steal electrons
Term
Do metals or nonmetals have more electron affinity?
Definition
Nonmetals
Term
Ground state
Definition
 electrons have the least energy and are easily drawn closer to the nucleus
Term
Excited state
Definition
Electrons have the most energy and move farther from the nucleus easily
Term
What did Democritus propose about the atom?
Definition
Said it was indivisible and had different shapes
Term
Thomson
Definition
Discovered electron (called corpucles), conducted cathode ray-tube expiriment, plum-pudding model
Term
Milliken
Definition
Discovered the charge of electrons, oil drop experiment
Term
Dalton
Definition
revised atomic theory, said: atoms could not be created, destroyed, or divided
Term
Rutherford
Definition
Gold foil experiment, discovered that atom was mostly made of empty space
Term
Bohr
Definition
Said electrons were in defind paths and orbits
Term
Heisenberg and Shrodinger
Definition
Revised modern day theory, said electrons in electron clouds.
Term
As you go to the right of the periodic table, the ionization energy and electron affinity __________
Definition
increases
Term

As you go _____ the periodic table, the atomic radius/size

increases

Definition
down
Term
As you go to the _______ of the periodic table, the size/radius decreases
Definition
right
Term
As you do down the periodic table, the ionization energy and electron affinity _________
Definition
decreases
Term
Molecular formula
Definition
The non-simple and complex formula
Term
Empirical formula
Definition
The simplest formula
Term
Ammonium
Definition
NH4+
Term
Hydroxide
Definition
OH-
Term
Nitrate
Definition
NO3-
Term
Acetate
Definition
C2H3O2-
Term
Cyanide
Definition
CN-
Term
Permanganate
Definition
MnO4-
Term
Sulfate
Definition
SO42-
Term
Carbonate
Definition
CO32-
Term
Phosphate
Definition
PO43-
Term
Chlorate
Definition
ClO3-
Term
Nitrite
Definition
NO2-
Term
Chromate
Definition
CrO4-2
Term
Dichromate
Definition
Cr2O7-2
Term
Sulfite
Definition
SO3-2
Term
Chlorite
Definition
ClO2-
Term
Hypochlorite
Definition
ClO-
Term
Perchlorate
Definition
ClO4-
Term
Hydrogen Carbonate
Definition
HCO3-
Term
Hydrogen Sulfite
Definition
HSO3-
Term
Hydrogen Sulfate
Definition
HSO4-
Term
Hydrogen Phosphate
Definition
HPO4-2
Term
Dihydrogen Phosphate
Definition
H2PO4-
Term

IMPORTANT-applies to many things in chemistry

 

What are the super 7 elements (that form bonds with another atom of their element type)

 

Ex:   X2 <----(this would be a super 7)

Definition

H, Cl, F, O, Br, I, N

(all of these would naturally appear like so:

H2, Cl2, F2, O2, Br2, I2, N2)

Term
Molar mass is measured with the unit ______
Definition
grams/mole (g/mole)
Term
How would you find the molar mass of anything?
Definition
You would add up the atomic masses of the individual elements that make it up.
Term
Find the molar mass of CaCl2.
Definition
around 110.98 g/mole
Term
How many molecules of O2 are found in 34 moles of O2?
Definition
2.05 x 1025 molecules of O2
Term
30 grams of CaCl2 contains _______ grams of Cl
Definition

around 19.17 grams of Cl


How to solve these:

 

1. Convert the initial quantity into moles (in this case, convert 30 grams of CaCl2 into moles of CaCl2)

 

2. Find the number of moles of the element that you are trying to find in the compound (in this case, we are tring to find moles of Cl that are in the compound CaCl2)

 

-do this by looking at the number associated with it in the compound (in this case, the number 2 is along with Cl, so there are 2 moles of Cl in the compound).

 

3. The number you got in step #2 is not the final answer, you must multiply everything you have done so far, like so (this is for this specific problem):

 

30 grams of CaCl2    1 mole of CaCl2    x   2 moles of Cl

                1                  110.98 grams CaCl2      1 mole  CaCl2                                                             


Then convert the answer you got (which should be in moles of Cl in this case) into whatever units the problem asks for (in this case, we will covert it into grams of Cl, and we will get: 19.17 grams of Cl)


 


Term

Al2(SO4)3 contains ________ moles of Oxygen

 

(you should not need to calculate anything) 

Definition
12 moles of Oxygen
Term
Find the percent composition of Na in the compound NaH2PO4
Definition

 around 19.17%,

 

The equation for these kinds of problems is:

 

Molar mass of element you are trying to find (in this case Na)

÷

Total molar mass of the compound 

|

|

V

And then multiply that answer by 100




Term
Convert 25 grams of Fe into molecules of Fe
Definition
around 2.69 x 1023 molecules of Fe
Term

How many moles of NaOH are required to form 0.2 moles of Al(OH)3 according to the equation:

 

3NaOH + AlCl3 = Al(OH)3 + 3NaCl

 

A) 0.1 mole   B) 1 mole   C) 3 moles   D) 0.6 moles

Definition

D) 0.6 moles


Here is the equation for these kinds of problems:


1: Take the intial quantity (in this case, 0.2 moles of Al(OH)3)


2: And then convert it into moles (it is already done for us in this problem, we have it in moles of Al(OH)3 already)


3: Find the number of moles of the element/compound that you are trying to find in the problem (in this case, we are trying to find moles of NaOH)

-in order to do this, look at the number in front of the element/compound in the equation (which is a 3 in front of NaOH in this equation, so 3 is the number of moles of NaOH in this equation)


4: That number of moles in step #3 is not the final answer, you must multiply and divide anything you did in this equation so far. I will show this below (this is for this one specific problem):


0.2 moles of Al(OH3)  x  3 moles of NaOH = 0.6 moles of NaOH          

1            1 mole of Al(OH3)                 



Term

1. What is Avagadro's Number? (the quantity)

 

2. What is it used to measure in Chemistry?

 

Definition

1. 6.02 x 1023

2. It is used to measure molecules (or atoms)

Term

Balance the equation:

_H2 + _NO = _H2O + _N2

Definition
2H2 + 2NO = 2H2O + 1N2
Term

How many bonds will Nitrogen form (the maximum)

You can use your periodic table

Definition
3
Term

Flourine would try to get 1 bond, why?

You can use your periodic table

Definition
Because it needs 1 more valence electron to have 8 valence electrons (it only has 7 to begin with)
Term

IMPORTANT-tricky

What is the charge of Aluminum?

Your periodic tables may help you, but not much

 

Definition
+3
Term

Ca is a metal and O is a nonmetal.

When the two form bonds with eachother, which one has more control over the valence electrons?

A. Ca                B. O

C. Neither of them have more power over the electrons

D. It is almost impossible to conceive which one because every bond is different

Definition
B. O
Term

Hydrogen forms _____ bonds (maximum)

Why?

 

Definition
1; because it only needs to make one bond, therefore giving up one electron, with another element in order to have 8 valence electrons
Term
What is the SI unit of pressure?
Definition
Psi (pounds per square inch)
Term

Pressure is caused by what?

 

Definition
The collisions of particles against walls and eachother.
Term
Which two states of matter have pressure?
Definition
Gas and Liquid
Term
What 3 factors can change the pressure of a gas?
Definition
The amount of gas, the temperature it is at, and the size of the volume in which it is kept in
Term

1. What is the ideal gas law?

2. What do the variables stand for?

3. What are the units used for each part of it?

Definition

1. PV=nRT

 

2. (pressure)(volume)=(number of moles)(0.0821)(temp)

 

3. (atm)(mL)=(moles)  (L x atm)  (K)

                           K x moles


Term
How do you convert °C to K (Kelvin)
Definition
°C + 273
Term
How do you convert Torr into atm (atmosphere pressure)
Definition
760 Torr = 1 atm
Term
How do you convert mmHg into atm (atmosphere pressure)
Definition
760 mmHg = 1 atm
Term

1. What is the Combined Gas Law?

2. What are the units used in it?

Definition

1.   P1V1  =  P2V2

      T1          T2    

 

2. YOU CAN USE ANY UNITS!!!! no joke, as long as you use the same ones throughout the entire equation.

But temperature (T) MUST be Kelvin (K)

Term

1. What is the other equation that begins with P = (blank)

                                                                     (blank)

,and includes density in it?

 

2. What do the variables stand for?

 

3. What are the units used in it?

Definition

1. P = DRT

          MM

 

2. (pressure) = (density)(0.0821)(temp)

                    (molar mass)

 

 

3. (atm) = (grams/L)   (L x atm)  (K)

                  ___________K x mole______

               (grams/mole)

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