1. Your teacher gives you an unknown substance: liquid X. You pour some of it into a dish, let it evaporate, and find a white residue in the dish. Which of the following best describes liquid X?
(Points : 1)
compound

element

pure substance

mixture



2. Which of the following chemical formulas represents an element?
(Points : 1)
H2O2

CO

CO2

O2



3. Which of the following is a homogeneous mixture?
(Points : 1)
cement

sand

ink

raisin bran cereal



4. Crude oil is a mixture of liquid hydrocarbons with boiling points that are close together. Which of the following methods would be the best way to separate them?
(Points : 1)
filtration

liquid chromatography

distillation

freezing



5. A biochemist has the following compounds: glucose (C6H12O6), sucrose (C12H22O11), fructose (C6H12O6), and cholesterol (C27H46O). Which of the following statements is true?
(Points : 1)
Sucrose has the most atoms and the most oxygen.

Cholesterol has the most atoms and the least oxygen.

Glucose has more oxygen than fructose.

Sucrose has more hydrogen than cholesterol.