Free response strategy gets most of the attention, but the multiple choice section is worth exactly half the exam, and a few specific habits move that score noticeably.
Always answer every question
There's no penalty for a wrong answer on the AP Chemistry multiple choice section, only a benefit for a correct one. That means a blank answer and a wrong guess are scored identically, so there's never a reason to leave a question empty, even a pure guess among four choices.
Time budget
60 multiple choice questions in 90 minutes works out to an average of a minute and a half per question. That's an average, not a rule for every single question, some will take 20 seconds and others three minutes, but tracking roughly where you should be partway through the section helps catch a pacing problem before it costs real time.
Use process of elimination deliberately
With only four answer choices, actively crossing out ones you know are wrong, even when you're not sure of the right answer, meaningfully improves the odds of a correct guess on a question you can't fully solve.
Read the question stem carefully
Words like "NOT" or "EXCEPT" flip what a question is actually asking, and they're easy to miss when moving quickly. A quick habit of underlining or circling these qualifiers as you read catches this specific trap before it costs a point on a question you otherwise knew.
Where students actually lose points here
Leaving a hard question blank
Since there's no guessing penalty, a blank answer is strictly worse than any guess at all. Marking something, even a pure guess, before moving on is always the better choice.
Spending too long on one difficult question
Losing several minutes on one hard question can cost multiple easier questions later in the section that never get seen. Moving on and returning later, if time allows, protects the rest of the section.
Missing a NOT or EXCEPT in the question stem
These qualifiers completely reverse what's being asked, and missing one under time pressure is one of the most common, avoidable multiple choice mistakes.
Half the exam, and worth the same attention
Multiple choice strategy is often treated as an afterthought next to FRQ prep, but the habits above are quick to build and apply to every single question on the section.
Common questions
Is there a penalty for guessing on AP Chemistry multiple choice?
No. Wrong answers and blank answers are scored identically, so there's never a reason to leave a question unanswered, even as a complete guess.
How much time should you spend per multiple choice question?
On average, about a minute and a half per question, based on 60 questions in 90 minutes. Some questions will take much less time and others more, but tracking your pace helps catch a timing problem early.
What's a common multiple choice trap on the AP Chemistry exam?
Question stems containing words like NOT or EXCEPT, which reverse what's actually being asked and are easy to miss when reading quickly under time pressure.