A Level Chemistry OCR Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Prepare for the A Level Chemistry OCR Exam with quizzes. Study with flashcards, multiple choice questions, hints, and explanations. Enhance your understanding and boost your confidence for success!

Start Multiple Choice Practice Test
Start Flash Cards

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

What does stoichiometry describe?

  1. The relationships between the physical states of substances

  2. The relationships between the pressure and volume of gases

  3. The molar relationship between the quantities of substances in a reaction

  4. The energy changes during a chemical reaction

The correct answer is: The molar relationship between the quantities of substances in a reaction

Stoichiometry specifically refers to the quantitative relationships between the reactants and products in a chemical reaction. It involves calculations that allow chemists to determine how much of each substance is consumed or produced based on balanced chemical equations. This relationship is essential for predicting yields, understanding reaction mechanisms, and performing calculations involving moles and mass. The other options do not accurately capture the essence of stoichiometry. For instance, descriptions of physical states, gas behaviors, or energy changes pertain to different concepts within chemistry, such as thermodynamics or gas laws, which do not focus on the quantitative relationships between the amounts of reactants and products in chemical reactions. Therefore, the focus on the molar relationship in option C defines stoichiometry correctly and is central to its application in chemical computations.

More Questions Like This