Chem 108 – Practice questions #1 (chapter one)
1. Find out the value of the following conversion: 45 km/hr = __________ m/s
A) 13
B) 0.045
C) 1.6  102
D) 2.7  103
E) 1.6  105
2. The answer of the following calculations equal:(10.07  7.395)
2.5
A) 6.988
B) 6.99
C) 7.0
D) 7
E) 17.5
3. There are __________ ng in a pg.
A) 0.001
B) 1000
C) 0.01
D) 100
E) 10
4. Gold has a density of 0.01932 kg / cm3 . What volume (in cm 3 ) would be occupied by a 33.3 g
sample of gold?
A) 0.663
B) 5.80  104
C) 5.80
D) 0.581
E) 1.72
5. Round the number 3456.5 to two significant figures.
A) 3.4 x 103
B) 3400
C) 3.46 x 103
6. Which one of the following is true?
A) Liter is the SI base unit for volume.
C) oC is the SI unit of temperature.
E) 1Gg equal to 106 g.
D) 3.5 x 103
E) 3000.0
B) 103 cm3 equal to a cubic decimeter.
D) g/cm2 is the SI unit of density.
7. Express the temperature 253 K in Fahrenheit degree (oF).
A) -20
B) 526
C) -29
D) 274
E) 253
8. The SI prefixes nano and mega represent --------- and ----------, respectively:
A. 109 and 10-6
B. 106 and 10-3
C. 10-9 and 106
D. 10-9 and 10-3
9. Which temperature change is the largest?
A. 10 ºC to 20 ºC
B. 273 K to 300 K
C. 10 ºF to 20 ºF
D. 30 oF to 20 ºC
10. Do the indicated arithmetic and give the answer to the correct number of significant
figures.
1.2790  (8.3 + 2.854) =
A. 14.3
B. 1.427 x 10
C. 14.32
D. 14.325
11. The SI unit for the pressure is ------------.
A. atm
B. torr
1
C. mmHg
D. N/m2
12. What is the density of Ar (M. M = 40 g/mol) if a 3.01 x 1025 atom sample has a volume of
1.12 x 103 L?
A. 3.56 g/L
B. 1.78 g/L
C. 4.46 g/L
D. 89 g/L
13. How many significant figures are there in 1.0500  109?
A. 5
B. 4
C. 3
D. 2
14. Express Avogadro’s number (602000000000000000000000) with 4 significant figures.
A) 602.0
B) 6.020 x 10-23
23
C) 6.020 x 10
D) 6.02 x 1023
15. Acceleration due to gravity of a free-falling object is 9.8 m/s2 . Express this in mm/ms2
2
(millimeters/millisecond ).
A. 9.8  109
B. 9.8  103
C. 9.8  106
D. 9.8  106
E. 9.8  103
16. A cube of an unknown metal measures 1.61 cm on one side. The mass of the cube is 36 g.
Which of the following is most likely the unknown metal?
Metal
Rh
Cu
Nb
V
Zr
3
Density(g/cm )
12.4
8.96
8.63
6.11
6.51
A. Cu
B. Rh
C. Nb
D. V
E. Zr
17. Which of the following is (are) the lowest temperature?
A. The freezing point of water
B. 5 °C
C. 25 °F
D. 280 K
18. A common English set of units for expressing velocity is miles/hour. The base SI unit for
velocity is -----A. km/hr
B. km/s
C. m/hr
D. m/s
E. cm/s
19. Calculate the heat that is needed to raise the temperature of 100.0 g of water 25.0 oC?
A) 2.5 kJ
B) 10.4 kJ
C) 2.5 x 104 J
D) 2.5 x 104 Kcal
20. If a piece of iron (mass 80.0 g) at 80.0 oC is placed in 80.0 mL of water at 20.0 oC, what would
be the final temperature of water? (density of water = 1.0 g/mL, specific heat for water and
iron: 4.18 and 0.45 J/g oC, respectively.)
A) 25.8 oC
2
B) 50.0 oC
C) 58.2 oC
D) 32.0 oC