Avogadro's Number
Avogadro's Number is equal to...
6.022 X 1023
The molar mass of sucrose (C12H22O11)
What is 342.34 g/mol.
Which is the most atoms:
22.99 g Na, 24.02 g C, 24.30 g Mg, 26.98 g Al
24.02 g Carbon. This is 2 moles vs 1 moles for the other substances
What is the percent of Hydrogen in HCl?
2.77%
Which of these is NOT an empirical formula
A) Mg3(PO4)2
B) C6H12O6
C) SO
B) can reduce to CH2O
The mass of 3.52 X 1024 molecules of water.
105 g
The molar mass of uranium hexafluoride. (UF6)
What is 352.03 g.
How many molecules are in 12.0 g NaCl?
1.24 x 1023 molecules
What is the percent of potassium in potassium carbonate.
What is 56.58%
K2CO3
What is the molecular formula of a compound with the empirical formula C2OH4 and a molar mass of 88 grams per mole.
C4O2H8
The number of atoms in 0.60 moles of Zinc.
3.6 x 1023 atoms
Determine the molar mass of magnesium nitrate
148.32 g/mol
The mass in grams of 8 moles of lead (II) oxide
2000 g
(ONLY 1 SIG FIG) PbO
The Percent composition each element in HCN (2sf)
What is H: 3.7% C: 44% N: 52%
A compound is found to contain 5.9% Hydrogen and 94.1% Oxygen and a molar mass of 34 g/mol. What are the empirical and molecular formula of this compound?
HO and H2O2
The number of moles in 3.7 X 1025 molecules of carbon dioxide.
What is 61 moles
Which of these is the largest mass?
3.00 mol hydrogen, 2.00 mol helium, 1.00 mol fluorine
1.00 mol fluorine
How many atoms are in 98.5 grams of gold.
3.01x1023 atoms
Percent oxygen in aluminum carbonate (4sf)
61.54%
Al2(CO3)3
What is the molecular formula for a compound that has 36.0% C, 4.0% H, 28.0% N and 32.0% O and a molar mass of 300 g/mol?
C9H12N6O6
The number of hydrogen molecules in 6.0 grams of hydrogen gas.
What is 1.8 X 1024 hydrogen atoms.
This is tricky because there are TWO atoms of hydrogen, so the molar mass is 2.02, NOT 1.01. Remember HONClBrIF are all diatomic if not bonded with any other element.
A chemist plans to use 435.0 grams of magnesium nitrate in a reaction. How many moles of the compound is this?
2.933 moles
Mg(NO3)2
How many molecules are in 100. g of potassium hydroxide?
1.07 x 1024 molecules KOH
What percentage of calcium hydroxide is calcium? (3sf)
54.1%
Ca(OH)2
A lab is performed to find a compound has a mass consisting of 10.47 g of copper which combines with phosphorus to form 12.51 g of copper phosphide. What is the empirical formula?
Cu5P2
You have 10.47 g Cu and 2.04 g P (12.51-10.47) when starting empirical formula math