Pure Substances and Mixtures

Which of the following is a pure substance?

• • A) Air

• • B) Distilled water

• • C) Salad dressing

• • D) Sand

Which item from the list below is a mixture?

• • A) Table salt

• • B) Pure gold

• • C) Ocean water

• • D) Oxygen gas

What does the term "purity" mean in chemistry?

• • A) A substance that has been mixed with another substance

• • B) A substance containing only one type of atom

• • C) A substance that contains only one type of molecule without impurities

• • D) A substance with multiple chemical elements

Which of the following is an example of a pure substance?

• • A) Air

• • B) Saltwater

• • C) Distilled water

• • D) Sugar dissolved in water

Question: Why is purity important in medicines?

• • A) It makes the medicine taste better

• • B) It ensures the medicine is free of harmful substances and effective

• • C) It makes the medicine more colorful

• • D) It increases the medicine's shelf life

Question: How can impurities affect food products?

• • A) They can enhance the flavor of the food

• • B) They can improve the food's appearance

• • C) They can pose health risks and affect food quality

• • D) They make the food last longer

Question: Which of the following is a characteristic of a pure substance?

• • A) It contains multiple different substances mixed together

• • B) It has a uniform composition throughout

• • C) It changes color when mixed with other substances

• • D) It can be easily separated into its components

Question: How can you differentiate between a pure substance and a mixture?

• • A) A pure substance will always be a liquid

• • B) A mixture will have a uniform composition and cannot be separated

• • C) A pure substance cannot be separated into simpler substances by physical means

• • D) A mixture has a fixed composition and cannot be altered