Moles <-> Particles
How do you convert moles into the number of atoms?
multiply by 6.02x1023
How do you convert mass into moles?
Divide by molar mass
divide by molar mass, then multiply by 6.02x1023
What is an empirical formula?
the lowest whole number ratio of a compound's elements
How many atoms of aluminum are in 1 mol?
6.02x1023 atoms
1 mole = 6.02x1023
What is the mass of 1 mole of MgCl2?
94 g
94g/mol is the molar mass of MgCl2
In scientific notation, what is the mass of 5.2x1019 atoms of sodium?
2.0x10-3g
(5.2x1019 / 6.02x1023) x 23
What is the empirical formula when there is 22.1% aluminum, 25.4% phosphorus, 52.5% oxygen?
AlPO4
22.1/27 = 0.81/0.81 == 1
25.4/31 = 0.81/0.81 = 1
52.5/16 = 3.28/0.81 = 4
What is the percentage of carbon in CO2?
27.3% carbon
12/44 x 100
A beaker contains 2.35x1027 molecules of NaCl, how many moles are in the beaker?
3903.7 mol
How many moles are in 0.01g of Ca(OH)2? Put your answer in scientific notation.
1.35x10-4 mol
0.01 / 74g/mol
How many molecules of CuCl2 are there in 732g?
3.3x1024 molecules
molar mass = 133.5g/mol
(732/133.5) x 6.02x1023
A compound contains 85.3% carbon and 14.3% hydrogen. What is the empirical formula?
CH2
85.3/12 = 7.14/7.14 = 1
14.3/1 = 14.3/7.14 = 2
What is the percentage of calcium in the compound calcium nitrate?
Ca(NO3)2
24%
40/164 * 100
How many molecules are in 27.3 mol of Fe2(SO4)3?
1.64x1025
27.3 x 6.02x1023
How many moles are in 3.8x10-5g of NaCl? Put answer in scientific notation.
6.55x10x10-7 mol
3.8x10-5 / 58
In the mole video, it was stated that 1 mole of basketballs grouped together would be the size of planet earth. What is the mass of 7.5x1024 basketballs (molar mass of basketballs = 3.41x1026g/mol)?
4.26x1027g
(7.5x1024 / 6.02x1023) x 3.41x1026
The empirical formula of a compound is CH4O, and the molar mass of the molecular formula is 192g/mol. What is the molecular formula?
C6H24O6
192 / 32 = 6
C1x6 H4x6 O1x6
What is the percentage of carbon in C8H10N4O2?
49.5%
96/194 * 100
How many moles are in 2.5x1019 molecules of Mg3(PO4)2?
4.15x10-5 or 0.0000415
2.5x1019 / 6.02x1023
How many moles are in 350g of Mg(NO3)2?
2.36
350 / 148.3
How many atoms are in 0.0088g of Ca3(PO4)2?
2.22x1020 atoms
( 0.0088 / 310.1 ) x 6.02x1023 x 13
A compound contains 49.5% carbon, 5.2% hydrogen, 28.9% nitrogen, and 16.4% oxygen. The molecular formula has a molar mass of 194g/mol. What is the molecular formula?
C8H10N4O2 (caffeine's formula)
49.5/12 = 4.125/1.02 4
5.2/1 = 5.2/1.02 = 5
28.9/14 = 2.06/1.02 = 2
16.4/16 = 1.02/1.02 = 1
Empirical formula = C4H5N2O
194/97 = 2
C4x2H5x2N2x2O1x2