Counting atoms by weighing
Define amu
What is atomic mass unit.
What is avagrodo's number?
6.022 X 1023
The ....... of a substance is the mass (in grams) of 1 mol of the substance.
What is molar mass
What is the formula for finding the persent of an element in a compound?
Mass fraction of a given element= mass of the element present in 1 mole of the compound/ mass of 1 mol of the compound
What is a formula of a compound that expresses the smallest whole number ratio of the atoms present?
What is empirical formula
calculate the mass in amu of a sample of iron that contains 15 atoms.
837.8 amu
One mole of oxygen atoms represents how mant atoms?
Avagrodos number; 6.022 X 1023
What is the molar mass of water?
18 g/ mol
Determing the mass percent of sulfur in sulfuric acid (H2SO4)
32.70%
What is the emperical formula of H2O2?
HO
calculate the number of argon atoms present in a sample of that has a mass of 3755.3 amu.
94 atoms
How many moles does 10 grams of aluminium have?
0.371 mol Al
What is the molar mass of calcium phosphate?
310.18 g/mol
A hydrocarbon has the formula C2H4. What is the percent by mass of carbon in the compound?
85.6
What is the empirical formula for CCL4
CCL4
What is the mass of 635 atoms of hydrogen?
640 amu
A chemical mole is equal to how many particles?
6.02 x 1023
Calculate the molar mass of a sample if a single molecule weighs 5.34 x 10-23g
32.2 g/ mol
What is the mass percent of Hydrogen in penicillin C14H20N2SO4?
6.453%
What is the empirical formula for C6H12?
CH2
How many atoms are in 19,695 amu of Xenon?
150 Xe atoms
Silicon has a mass of 5.68 x 10-3 g of Si, how many silicon atoms are present?
1.22 x 1020 si atoms
What is the molar mass of C12H22O11?
342.30 g/ mol
Determine the percentage of composition (by mass) of H2SO4
H= 2.06%
S=32.69%
O=65.25%
SF2