Atoms
How many grams in 6.02 x 10^23 atoms C?
12 g C
What is the mass (g) of 1.00 mol Li?
7 g Li
Which of the following samples has more moles?
A. 23 grams of NaCl
B. 20 grams of LiF
Sample B has 0.7 moles and Sample A has 0.4 moles
A 68 gram compound made up of Sodium and Sulfur contains 32 grams of sodium. What is the percent composition of the compound?
Sodium-47.1%
Sulfur-52.9%
How many atoms in 6.755 mol Pb?
4.068 x 10^24 atoms Pb
Which of the following samples has more atoms?
A. A sample of 0.5 moles of NaCl
B. A sample of 0.3 moles of MgO
Sample A.
Determine the empirical formulas for the compound with the following percent compositions:
40.0% carbon, 6.7% hydrogen, and 53.3% oxygen
CH2O
How many grams in 10.5 x 10^23 atoms Mg?
41.8 g Mg
How many moles of H2 gas are in 60 L?
2.7 moles
Without doing calculations, is 30 grams of H2O going to be more or less than a mole? Briefly explain.
More than. 30 grams is larger than the molar mass of H2O
What is the molar mass of Ca(OH)2?
74 g/mol
Dichloroethane, a compound that is often used for dry cleaning, contains carbon, hydrogen, and chlorine. It has a molar mass of 99 g/mol. Analysis of a sample shows that it contains 24.3% carbon and 4.1% hydrogen. What is its empirical formula?
CH2Cl
How many atoms in 0.250 mol S?
1.51 x 10^23 atoms S
How many moles in 2.25 x 10^25 atoms Zn?
37.4 mol Zn
What is the molar mass of Al(NO3)3?
213 g/mol
What is the percent composition for each element of HCN?
H: 3.7%
C: 44.4%
N: 51.8%
How many atoms in 40.5 L of CO2?
1.1x1023 atoms
How many grams in 8.42 x 101 atoms Br?
1.1x10-20 g Br
What is the empirical formula of C5H10?
CH2
What are two different molecular formulas that could be from the empirical formula C2H4O?
(Multiple answers)
Some answers could be:
C4H8O2
C6H12O3
C8H16O4