1. Which of the following represents a valid hypothesis?
A) Neon does not react with oxygen.
B) Sodium metal reacts violently with water.
C) Lead is soft and malleable.
D) Oxygen is a gas at room temperature.
E) Metals tend to lose electrons.
2. Two or more substances in variable proportions, where the composition is constant throughout are
A) a compound.
B) an element.
C) a heterogeneous mixture.
D) a homogeneous mixture.
E) a crystalline solid.
3. Which of the following are examples of physical change?
A) dew forms on a blade of grass
B) a halloween light stick glows after shaking
C) an egg solidifies during cooking
D) a hydrogen balloon explodes when contacted with a flame
E) None of the above are physical changes.
4. Which of the following measurements are NOT equivalent?
A) 25 mg = 0.025 g
B) 183 L = 0.183 kL
C) 150. msec = 0.150 sec
D) 84 cm = 8.4 mm
E) 24 dL = 2.4 L
5. Which of the following is the lowest temperature?
A) 42°C
B) 57°F
C) 318 K
D) All of these temperatures are all equal.
6. What answer should be reported, with the correct number of significant figures, for the following calculation? (965.43 × 3.911) + 9413.4136
A) 13189
B) 13189.2
C) 1.32 × 104
D) 1.3 × 104
E) 1.319 × 104
7. What is the volume (in cm3) of a 63.4 g piece of metal with a density of 12.86 g/cm3?
A) 4.93
B) 19.5
C) 0.425
D) 6.65
E) none of the above
8. Methane and oxygen react to form carbon dioxide and water. What mass of water is formed if 3.2 g of methane reacts with 12.8 g of oxygen to produce 8.8 g of carbon dioxide?
A) 7.2 g
B) 8.8 g
C) 14.8 g
D) 16.0 g
9. The mass of gold in an earring was analyzed to be 0.837 g. If the true value for this mass of gold is 0.864 g, calculate the percent error.
A) 3.1%
B) 96.9%
C) 1.03%
D) 3.23%
10. To the correct number of significant figures, what is the temperature reading on the following Celsius thermometer?
A) 15°C
B) 15.06
C) 15.6°C
D) 15.67°C
E) 16°C
11. A piece of metal ore weighs 8.250 x 10-3 kg. When a student places it into a graduated cylinder containing water, the liquid level rises from 21.25 mL to 26.47 mL. What is the density of the ore (g/mL) ?
12. The recommended adult dose of Elixophyllin , a drug used to treat asthma, is 6.00 mg/kg of body mass. Calculate the dose in milligrams for a 115-lb person. 1 lb = 453.59 g.
13. A graduated cylinder has 20 ml (cm3) of water placed in it. An irregularly shaped rock is then dropped in the graduated cylinder and the volume of the rock and water in the cylinder now reads 30 ml (cm3). The mass of the rock dropped into the graduated cylinder is 23 grams.
a.) Find the volume of the rock dropped into the graduated cylinder.
b.) Find the density of the rock dropped into the graduated cylinder.
14. The distance between Happyville and Giggleland is 60 miles. How far is this in kilometers?