Chemistry is where a lot of strong students hit their first real wall. It asks them to hold three things at once — an abstract model of matter they cannot see, a set of rules governing how it behaves, and the arithmetic to quantify it — and most courses move too fast for any of the three to settle properly.
Mackler Associates provides one-on-one chemistry tutoring in St. Louis, covering both standard high school chemistry and AP Chemistry. Every session is taught by Jason Marks personally.
This is the single most useful thing to understand about chemistry struggles, and it is the thing most tutoring misses.
Look at what actually costs students points. Stoichiometry is proportional reasoning and unit conversion. Molarity is a ratio. Gas laws are algebraic rearrangement. Limiting reagent problems are multi-step setups where one early slip propagates through everything after. Equilibrium is fractions.
A student who is shaky on ratios, unit conversion, or rearranging equations will struggle in chemistry no matter how well the chemistry itself is explained — and will usually believe the problem is chemistry. It often isn’t.
That matters here because mathematics is the foundation of what Jason Marks has taught for over two decades, from pre-algebra through calculus. When a chemistry grade is slipping, the first job is working out whether the gap is conceptual, mathematical, or procedural. Those three call for completely different responses, and treating one as another wastes everyone’s time.
Foundations — atomic structure, the periodic table, naming and formulas, and the bonding models everything later depends on. Students who are guessing at nomenclature are guessing at everything downstream.
Quantitative Chemistry — moles, stoichiometry, limiting reagents, percent yield, molarity and dilution. This is where most grades are won or lost, and where the math-versus-chemistry distinction matters most.
Reactions and Equations — balancing, reaction types, predicting products, and net ionic equations.
Gas Laws and States of Matter — the gas laws, phase changes, and the kinetic molecular theory behind them.
Thermochemistry, Kinetics and Equilibrium — energy changes, reaction rates, Le Châtelier’s principle, and acid-base chemistry including pH and titration.
AP Chemistry is a different workload from standard chemistry, and students who coasted through the regular course are often caught out by it. The content moves faster, the quantitative demands are heavier, and the exam rewards a kind of reasoning that classroom tests frequently do not.
Preparation here covers the course content alongside the specific demands of the exam — the multiple-choice section’s pace, the free-response questions that ask students to justify a claim with evidence rather than just produce a number, and the experimental design questions that reward understanding why a procedure works rather than recalling that it does.
The quantitative sections are where most AP students lose ground, and that is the same work described above: stoichiometry, equilibrium calculations, thermodynamics, and kinetics are all mathematics applied to chemistry. A student who is fluent there has a far easier time with everything else on the exam.
Sessions work from released College Board materials and past free-response questions, because the format itself is a skill and it is best learned on the real thing.
Jason Marks teaches every session himself. There is no roster, no assignment process, and no handoff between tutors partway through a program.
He was a National Merit Scholar, attended the Honors College at the University of Missouri, graduated magna cum laude and Phi Beta Kappa, and holds a J.D. from Washington University School of Law. Since 2000 he has taught students from elementary school through graduate programs, across a range that runs from fractions to calculus.
The practical difference is continuity. In week eight he remembers exactly what happened in week one — which explanation landed, which one didn’t, and which gap is still open. Nothing is re-diagnosed and nothing is re-explained.
This is a program, not a booking service. Tutoring is delivered as a twenty-hour program with a fixed fee, payable in full at the start.
That structure exists for a reason. Chemistry gaps do not close in two sessions, and a student who comes in only when a test is looming tends to stay exactly where they started. Committing to a program means the work can be sequenced properly — diagnostic first, then a plan built around what that diagnostic found, with time to consolidate before moving on.
It also means families know the cost up front, with no meter running.
If you are looking for occasional homework help charged by the hour, this is not that, and we will say so at the consultation rather than take the booking.
Sessions are held at our office on North Mason Road in Creve Coeur, just south of Olive Boulevard, with parking on site.
In-person matters in chemistry for the same reason it matters in math. Watching a student set up a stoichiometry problem on paper — seeing where the pencil stops, which conversion they skip, where they start guessing at units — shows you the actual gap. A screen hides all of it.
Families come from across St. Louis County, including Chesterfield, Ladue, Town and Country, Frontenac, Olivette, Clayton, Kirkwood, and University City. See all the areas we serve.
The first conversation is free and involves no commitment. Bring recent tests or graded work if you have them — a marked-up chemistry test is the fastest way to see whether the problem is the chemistry, the math underneath it, or how the student is approaching the questions.
If chemistry turns out to be a symptom of something else, we will tell you that too.
Schedule your free consultation or call (314) 434-4431.
Also see: math tutoring · algebra tutoring · science and academic tutoring
Atomic structure, the periodic table, naming and formulas, bonding, balancing equations, stoichiometry, moles and molarity, gas laws, thermochemistry, kinetics, equilibrium, and acid-base chemistry — the content of a standard high school chemistry course.
Usually the math. Stoichiometry, molarity, gas laws and equilibrium are all quantitative, and a student who is shaky on ratios or unit conversion will lose points on problems they conceptually understand. That is a different problem from not understanding chemistry, and it is fixed differently. The initial diagnostic is designed to tell the two apart.
Earlier than most families expect. Chemistry builds relentlessly — nomenclature feeds formulas, formulas feed equations, equations feed stoichiometry — so a gap opened in September is still costing points in March. Starting when the first test comes back disappointing is far more effective than waiting for the semester grade.
Sessions are held in person at our Creve Coeur office. For problem-solving subjects especially, watching a student work on paper reveals things a screen does not.
Yes. AP Chemistry preparation covers the course content alongside the exam’s specific demands — the pace of the multiple-choice section, the free-response questions that require justifying a claim with evidence, and experimental design. Sessions work from released College Board materials so students practise on the real format.