Acids and Bases: Practice Questions with AnswersCurriculum: Acids and BasesGrades: 7–9Questions: 12Mode: Practice Warm up on what acids and bases are and how we tell them apart (easiest level). These are the real questions from this STEPCAI practice lesson. Read each question, pick your answer, then open Show the answer to check yourself and read why it is right. On STEPCAI the same lesson runs interactively: you click an answer and get instant feedback, and a free account keeps your scores. 1. On the pH scale, a value of 7 means a substance is...- a strong base
- neutral
- flammable
- a strong acid
Show the answerAnswer: B. neutral
A pH of 7 is neutral - neither acidic nor basic. Pure water is a good example. 2. A substance with a pH of 2 is...- acidic
- neutral
- basic
- a metal
Show the answerAnswer: A. acidic
A pH below 7 means acidic, and 2 is quite acidic (like lemon juice). 3. A substance with a pH of 12 is...- basic (alkaline)
- neutral
- pure water
- acidic
Show the answerAnswer: A. basic (alkaline)
A pH above 7 means basic, and 12 is strongly basic (like bleach or soapy water). 4. Which of these is a common household ACID?- bleach
- soap
- baking soda
- lemon juice
Show the answerAnswer: D. lemon juice
Lemon juice contains citric acid, giving it a sour taste and a low pH. 5. Acids typically taste...- salty
- bitter
- sour
- sweet
Show the answerAnswer: C. sour
Acids taste sour - think of lemons or vinegar. (Never taste lab chemicals, though!) 6. Litmus paper is used to...- measure how hot or cold a liquid is
- weigh how heavy a substance is on a scale
- check whether a liquid can carry electricity
- test whether something is an acid or a base
Show the answerAnswer: D. test whether something is an acid or a base
Litmus paper is an indicator: it changes color to show if a substance is acidic or basic. 7. Blue litmus paper turns RED in the presence of...- pure water
- salt
- a base
- an acid
Show the answerAnswer: D. an acid
Acids turn blue litmus red. (Bases turn red litmus blue.) 8. Bases often feel...- sticky like glue
- gritty like sand
- warm and dry
- slippery or soapy
Show the answerAnswer: D. slippery or soapy
Bases feel slippery or soapy - one reason soap is a base. 9. Which everyday liquid is closest to NEUTRAL (pH near 7)?- soapy water
- pure water
- vinegar
- lemon juice
Show the answerAnswer: B. pure water
Pure water has a pH of about 7, making it neutral. 10. The pH scale usually runs from...- -7 to 7
- 0 to 14
- 0 to 100
- 1 to 10
Show the answerAnswer: B. 0 to 14
The common pH scale goes from 0 (very acidic) to 14 (very basic), with 7 neutral. 11. When an acid and a base react together, the process is called...- magnetism
- neutralization
- evaporation
- freezing
Show the answerAnswer: B. neutralization
An acid reacting with a base is neutralization; it typically produces water and a salt. 12. Which of these is a common household BASE?- orange juice
- vinegar
- baking soda
- soda pop
Show the answerAnswer: C. baking soda
Baking soda is a mild base, which is why it can neutralize acids (like calming an acidic stomach). More free middle school sample lessonsSee all free sample lessons »
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