Fill-in-the blank.  Make sure to include the plus and negative signs.  Do not write spaces.  (Example: If the answer is positive four enter +4 not + 4).  The chromium atom in K2CrO4 has an oxidation number of [1].  The carbon atom in CO has an oxidation number of [2] The oxidation number of hydrogen in H2 is [3].

The molarity of a solution prepared by diluting 43.72 mL of 1.005 M aqueous K2Cr2O7 to 500. mL is __________. 

Bromine is a red liquid at 25°C.  Its density is 3.12 g/cm3.  What is the mass of 9.01 cm3 of liquid bromine?

Each sample in the figure below contains 6.022 X 1023 molecules or formula units. Which, if any, has the most mass?    

A US barrel is 4.21 cubic feet.  Express this volume in liters. (1L= 1dm3, 1m = 3.28 ft)

How many moles of carbon dioxide, CO2, are there in 56.02 g of carbon dioxide? (If you wish, you can show math work for possible partial credit.)  

Aluminum metal reacts with iron(II) sulfide to form aluminum sulfide and iron metal. What is the stoichiometric coefficient for aluminum when the chemical equation is balanced using the lowest whole-number stoichiometric coefficients?

Balance the following equations, if the value is 1, enter the 1:      [1_1] C3H8O(l) + [1_2] O2(g) → [1_3] CO2(g) + [1_4] H2O(l)

  A piece of a metal alloy with a mass of 114 g was placed into a graduated cylinder that contained 25.0 mL of water, raising the water level to 42.5 mL.  What is the density of the metal?

Identify the spectator ions in the following molecular equation.            LiCl(aq) + AgNO3(aq) → AgCl(s) + LiNO3(aq)