Author: Anonymous

A [m] gram sample of potassium chlorate was decomposed according to the following equation:2KClO3 → 2KCl  +  3O2How many moles of oxygen are formed?

The density of gasoline is [d] g/mL at 20 oC.  What is the mass of one gallon of gasoline? (1 qt = 0.9463 L, 4 qt = 1 gal) (answer in grams)

Suppose the following reaction is carried out starting with 103 grams of Ca3(PO4)2 and 75.0 grams of H2SO4.  Which substance is the limiting reactant?  (Hint:  calculate the T.Y. for calcium sulfate first.)Ca3(PO4)2  +  3H2SO4 →  3CaSO4  +  2H3PO4

What volume (in liters) is occupied by [m] g of methane, CH4, at [t]  oC and [p] atm?

Give (in order) the correct coefficients to balance the following reaction:H2SnCl6  +    H2S →  SnS2  +    HCl

An oxygen sample has a volume of [v] L at [t] oC and [p] torr.  How many oxygen molecules does it contain?

The molar mass of an insecticide, dibromoethane, is 187.9.  Its molecular formula is C2H4Br2.  How many atoms of carbon are in a sample of dibromoethane weighing [m] g?

When 19.8 g C2H6 and [m] g O2 react to form CO2 and H2O, how many grams of water are formed? Make sure you balance the equation first.  C2H6  +  O2  →  CO2  + H20

A sample of an element with a mass of [m] g was dropped in a graduated cylinder containing 22.30 mL water.  The volume of the water plus the sample was [v] mL.  What is the density of the element?

A scientist obtains the number 0.045006700 on a calculator. If this number actually has four (4) significant figures, how should it be written?