1 Which of these would be best to measure 12.6 mL of liquid ethanol?
A: 25 mL beaker
B: 25 mL volumetric flask
C: 25 mL Erlenmeyer flask
D: 25 mL graduated cylinder
D: 25 mL graduated cylinder
An example of a chemical property is —
F: mass of a substance per unit volume
G: ability to dissolve in solution
H: point where solid becomes liquid
J: tendency to undergo oxidation
J: tendency to undergo oxidation
A compound has a mass of 2.66632 x 10^2 g/mol. The number of significant figures in this mass is -
F: 2
G: 4
H: 5
J: 7
H: 5
26 A student hypothesizes that bromine (Br) has different chemical properties from krypton (Kr). The periodic table supports this hypothesis by indicating that —
F: bromine is a metal while krypton is a nonmetal
G: one mole of bromine is heavier than one mole of krypton
H: bromine and krypton are members of the same family
J: bromine and krypton have different numbers of valence electrons
J: bromine and krypton have different numbers of valence electrons
14 If a sample has a mass of 1.25 x 102 g and a volume of 51 mL, what is its density?
F: 0.00025 g/mL
G: 0.0125 g/mL
H: 2.5 g/mL
J: 250 g/mL
H: 2.5 g/mL
Which of the following is a chemical change?
F: Salt is dissolved in water.
G: Water is boiled on a stove.
H: Gasoline combusts in an engine.
J: Copper metal is stretched into a long wire.
H: Gasoline combusts in an engine.
34 Which is the best use for a fume hood?
F: Storing glassware
G: Removing toxic vapors
H: Covering volatile compounds
J: Mixing chemicals that release O2
G: Removing toxic vapors
47 Which of these best describes the basis on which new scientific ideas are accepted or rejected?
A: Popular support
B: Historical support
C: Compelling evidence
D: Moral and ethical beliefs
C: Compelling evidence