1
"Competence in Chem" Quantitative skills Portion (Written Test)
This includes numerical problems such as conversions (e.g. between mass, moles,
volumes, pH, etc), Avogadro's number, making and diluting solutions of different
concentrations, balancing equations, stoichiometry problems, limiting reagent problems,
problems related to equilibria, and thermodynamics.
These are skills you should have learned in Chem. Prin. lecture and labs, Organic labs,
Instrumental lecture and labs, and Physical chemistry.
Typical questions (with answers) are listed on the following web page from the American
Chemical Society (ACS).
http://www.acs.org/content/acs/en/education/students/highschool/olympiad/pastexams.ht
ml
You should focus only on the numerical and calculation type of questions above.
For example...
Local Exam 2011 Questions # 7, 8, 9, 12, 14, 18, 20, 21, 36, 52.
Local Exam 2001 Questions # 10, 11, 12, 13, 17, 24, 27, 28, 29, 34
The link currently works, but if it changes the info can be found from the ACS page using
the following progression:
American Chemical Society > Education > Students > High School > Chemistry
Olympiad > Past Exams
Here are four illustrative examples (solved answers are at the end).
(EASY) How many grams of KCl do we need to make 1.0 L of a 1.0M KCl solution ?
(MEDIUM) If 10 mL of a 1.0 M KCl solution is added to 1.0 L of water, then what is the
concentration of KCl ?
(HARDER) A 1.50 mL sample of sulfuric acid is titrated with 1.47M sodium hydroxide.
The endpoint is reached with 23.70 mL. What is the molarity of the sulphuric acid ?
(HARDEST)A mineral containing iron(II) sulfide but no other sulfides is treated with
excess hydrochloric acid to produce hydrogen sulfide. If a 3.15 g sample of the mineral
yields 448mL of hydrogen sulfide gas (measured at 0.0oC and 760 mmHg), what is the
mass percentage of iron(II) sulfide in the sample ?
You will require a calculator. Other electronic devices, like cell phones or iPads, are not
acceptable.
