Mole

Question 1

explain a Mole. what is the symbol?

Answer 1

the quantity that chemists use to measure elements and compounds
symbol: mol

Question 2

what is Avogadro’s #? what is the symbol?

Answer 2

the # of atoms or molecules in 1 mol
approximately 6.02x10^23
symbol: NA

Question 3

What is the process of calculating how many atoms are in 1 mol?

Answer 3

6.02x10^23 x x
Ex:
How many atoms are in 3 moles?
6.02x10^23 x 3
= 1.806 x 10^24 atoms in 3 moles

Question 4

what is the rule for scientific notation and rounding the decimal point? (when calculating moles)

Answer 4

when moving the decimal point to the left, you must change the 23 in 6.02x10^23, it must become a 24 instead of a 23

Question 5

What is molar mass?

Answer 5

-the mass of one mole of a substance
-the atomic molar mass of an element is the average mass in grams of one mole of atoms of that element
Ex: molar mass of carbon is 12.01g/mol

Question 6

what is the process for finding the molar mass of compounds?

Answer 6

-list the elements seperately
-find the molar mass of each element
-multiply the molar mass by how many atoms are present
-add the individual masses together
NOTE: separate polyatomic compounds
Ex: H2O
H 1.01 x 2 = 2.02
O 16.00 x 1= 16.00
2.02 + 16.00 =18.02 g/mol

Question 7

What is the formula used for a molar equation?

Answer 7

m=n x M
m = mass (grams)
n = quantity of matter (moles)
M = molar mass (g/mol)
the # of moles of a substance is related to its molar mass

Question 8

What are the variations for the molar equation formula? (m = n x M)

Answer 8

1. n = m
   M
2. M = m
   n

Question 9

true or false: when calculating molar equations, you round the decimal point

Answer 9

False! Sig digs don’t matter! You dont round

Question 10

What is molar ratio?

Answer 10

the coefficients in a balanced chemical equation indicate the # of moles required for the reaction
Ex:
Cl2(g) + H2(g) —> 2 HCl(aq)
(1mol) (1 mol) (2 mols)