the mineral hausmannite is a compound of Mn and O. If hausmannite is 72% Mn by mass, what is the empirical formula of hausmannite?

The density of silver is 10.5 g/cm^3. How many silver atoms are present in a silver bar that measures 0.100 m x 0.050 m x 0.010 m?

Which copper ore contains the highest percentage of copper by weight? Mathematically document your answer  (Cu=63.5; S=32.0; O=16.0; H=1.00; C=12.0) Brochantite CuSO4 x 3 Cu(OH)2 or Azurite 2 CuCO3 x Cu(OH)2  ?

If 5.467 g of KAl(OH)4 was the limiting reagent in the synthesis of Alum, calculate the mass of Alum that is produced if the yield is 98.00%. (molar mass of KAl(OH)4= 134.108 g/mol; molar mass for KAl(SO4)2•12 H2O =474.4 g/mol)

Rank the following compounds in order of increasing mass percentage of nitrogen: NO, NO₂, N₂O.

Carborundum is silicon carbide, SiC.  It is prepared by the reaction of pure sand, SiO2 with carbon at high temperature.  CO is the other product of this reaction.  Given the equation  SiO2 + 3C results in 2CO + SiC  calculate how much SiO2 is required to produce 3.00 kg of SiC.

Explain how the atomic mass unit (amu) is defined and explain how the definition of an amu, in turn, determines the value of Avogadro’s number (NA), which is 6.0221 x 1023

Dolomite, a type of rock found in some petroleum reservoirs, is a mixture of CaCO3 and MgCO3. If the mass percent of magnesium in a sample of dolomite is 13.2%, what is the mass percent of calcium in this sample?

Consider a 134.5 g sample of the compound manganese(IV) perchlorate.What is the molar mass of manganese(IV) perchlorate?

a) Determine the empirical formula of a compound that contains sulfur and oxygen. It has been determined that 59.95% of the mass of this compound is oxygen. [   b) The molar mass of the compound is determined to be 240.189 g/mol. What is the molecular formula of the compound?