Empirical Formula
Determine the empirical formula if the analysis of a compound shows that it is 9.2% B and 90.8% Cl.
BCl3
A brown gas has the empirical formula NO2. Its experimental molar mass is 46 g/mol. What is its molecular formula?
NO2
Calculate the percentage composition of Sr in SrBr2.
35.41%
How many moles of xenon does 5.66 x 10^23 atoms equal?
0.94 moles
The mass of a Cu-63 atom is 62.94 amu, and that of a Cu-65 atom is 64.93 amu. Using this data find the average atomic mass of Cu.
63.55 amu
The analysis of a compound shows that it is 27.0% Na, 16.5% N, and 56.5% O. What is the empirical formula?
NaNO3
Benzene has the empirical formula CH and an experimental molar mass of 78 g/mol. What is its molecular formula?
C6H6
Calculate the percentage composition of O in ammonium nitrate, NH4NO3.
59.96%
How many moles are in 75 grams of sodium.
3.26 moles
Uranium is used in nuclear reactors and is a rare element on earth. Uranium has three common isotopes. If the abundance if U-234 is 0.01%, the abundance of U-235 is 0.71%, and the abundance of U-238 is 99.28%, what is the average atomic mass of uranium?
237.98 amu
A magnetic iron oxide is 72.4% iron and 27.6% oxygen. What is the empirical formula?
Fe3O4
Determine the molecular formula for a compound with the empirical formula CoC4O4 and a molar mass of 341.94 g/mol.
Co2C8O8
Calculate the percentage composition of chloride in Magnesium Chloride.
74.47%
How many molecules are there in 4.224 moles of acetic acid?
2.54 x 10^24 molecules.
Rubidium is a soft, silvery-white metal that has two common isotopes, Rb-85 and Rb-87. If the abundance of Rb-85 is 72.2% and the abundance of Rb-87 is 27.8%, what is the average atomic mass of rubidium?
85.56 amu
An oxide of phosphorus is 56.34% phosphorus, and the rest is oxygen. Calculate the empirical formula for this compound.
P2O3
Oleic acid has the empirical formula C9H17O. If the experimental molar mass is 282 g/mol, what is the molecular formula of oleic acid?
C18H34O2
Calculate the percentage composition of all elements of Calcium Fluoride.
Ca= 51.33%
F2= 48.67%
Find the mass in grams of 3.990 x 10^25 molecules of CH4. The molar mass of CH4 is 16.05 g/mol.
1.06 x 10^3 grams
Copper used in electric wires comes in two isotopes; Cu-63 and Cu-65 has an atomic mass of 62.9298 amu and an abundance of 69.09%. The average atomic mass between these two isotopes is 63.456 amu. Calculate the actual atomic mass of Cu-65.
64.930 amu
Determine the empirical formula for a compound made up of 52.11% carbon, 13.14% hydrogen, and oxygen.
C2H6O
Determine the empirical formula of a compound that has 50.1% S and 49.9% O. Then calculate the compounds molecular formula if the compounds experimental molar mass is 64 g/mol.
EF= SO2
MF=SO2
What is the percent composition of all elements for Magnesium Nitride.
Mg= 72.25%
N= 27.76%
How many molecules are in 27 grams of NaCl?
2.78 x 10^23 molecules
Given the information; There are two isotopes of an element (X-6 and X-7) Isotope X-6 has a mass of 6.015 and a percent abundance of 7.5% and X-7 has a weight of 7.016, calculate the atomic mass of unknown element X. Then, identify the unknown element, which is used medically to treat some mental disorders.
6.94 and Li