Mole Concepts
What is a mole
6.02 x 1023
how many moles are in 6.02 x 1023 particles?
1 mole
What is the formula for percent composition?
Part/whole x 100
88.8% copper; 11.2% oxygen
Cu2O
100 people were estimated to arrive for an event but 90 actually showed up. What is the percent error?
10%
A reaction should produce 2.0 grams of water but only 1.6 grams of water were recovered. What is the percent yield?
80%
how many grams are in 2.5 moles of nitrogen?
35g N
Percent of hydrogen in water?
11% hydrogen in H2O
30.4% nitrogen; 69.6% oxygen
NO2
How many atoms of Hydrogen are in (NH4)2O
8
Which has the most particles?
5 moles oxygen
5 moles iron
5 moles lead
all the same
How many particles are in .043 moles of Neon?
2.6 x 1023 atoms Ne
Percent bromine in CuBr2
72% bromine
38.7% chlorine; 61.3% fluorine
ClF3
what is the molar mass of FeSO4
152 grams/mole FeSO4
which has the least amount of particles?
5 grams of oxygen
5 grams of iron
5 grams of lead
5 grams of lead
How many grams are in 5.0 x 1023 particles of Calcium?
33 grams of Calcium
Percent of Sodium in NaOH
57.5% Sodium
6.01 grams of carbon was heated and produced 38.01 grams of a carbon and oxygen gas. What is the empirical formula?
CO4
Molar mass of calcium phosphate Ca3(PO4)2
310.18g Ca3(PO4)2
10g of Cobalt Chloride DIHYDRATE (CoCl2-2H2O) is heated to form the dehydrated salt. It calculated in the lab to contain 2.00 grams of water. What is the theoretical % of water and the percent yield?
2.17 grams H2O and a 92.2% yield.
how many particles are in .0005 grams of Arsenic?
4.0 x 1018 atoms As
Percent Hydrogen in (NH4)2S
12% Hydrogen
A compound with the following composition has a molar mass of 60.10g/mol: 39.97% carbon; 13.41% hydrogen; 46.62% nitrogen. Find the molecular formula.
C2H8N2
Dopamine is the chemical in your brain that controls positive emotions in your brain. The formula is C8H11NO2 whats is the molar mass?
153 grams per mole