#. Trinitrobenzene is a compound of C, H, N, and O. Its percent composition by mass includes
33.8% C, 19.7% N, and 1.42% H. The formula mass is around 213 amu. What is the
molecular formula of trinitrobenzene? (Hint: What is the percent O?)
Mol. Form. =
#. How many grams of chlorine are needed to react with 195.0 g of chromium to form
chromium (III) chloride?
#. How many milligrams of phosphorus are there in 1.37 grams of Mg3(PO4)2?
#. The empirical formula for a simple carbohydrate is CH2O. If its formula mass is 240. amu,
what is its molecular formula?
#. Sodium citrate is a tart-flavored food additive used in bratwurst sausage. It has a percent
composition by mass of 26.7% Na, 27.9% C, 1.95% H, and 43.4% O. What is its empirical
#. If you do not use a balanced equation when solving stoichiometry problems, what law will
you violate as a result?
#. Under certain conditions glucose can react with hydrogen gas to produce methanol.
C6H12O6 + 6 H2 ïƒ 6 CH3OH
How many grams and how many liters of methanol can you produce from 238.7 g of
glucose and excess hydrogen gas? The density of methanol is 0.792 g/mL.
#. One reaction used to inflate airbags in cars is:
3 NaN3 ïƒ Na3N + 4 N2
How many moles of N2 would you produce from 357.0 grams of NaN3?
#. The combustion reaction for methanol is:
2 CH3OH + 3 O2 ïƒ 2 CO2 + 4 H2O
a. If 13.0 g CH3OH react with 15.0 g O2, which compound is the limiting reagent??
b. How many grams of CO2 could be produced?
c. Calculate the number of moles of the excess reagent remaining at the end of the reaction.
#. The actual yield of a product is almost always smaller than the theoretical yield. Why?
#. TNT (C7H5N3O6) can violently decompose according to the following reaction:
2 C7H5N3O6 ïƒ 3 N2 + 12 CO + 5 H2 + 2 C
a. How many grams of CO could be produced from 3.00 x 103 g of TNT?
b. If this reaction has a percent yield of 90.0%, how many grams of CO would you