1

CHEMISTRY 1: FAC 0015

Tutorial 1 (Chapters 1-2) 1. Label the following as either a physical (P) or chemical (C) process:

a. Corrosion of aluminium metal b. Melting of ice c. Condensation of water d. Digesting a candy bar e. Explosion of nitroglycerin f. Burning of a metal in air g. Conducting electricity h. Boiling of ethanol

2. Identify the following properties as either intensive (I) or extensive (E) property:

a. triple point of water b. mass of NaCl c. concentration d. density of acetone e. molar volume of O2 gas f. vapor pressure of hexane at 25°C

3. Perform the following conversions and express the answer with the appropriate number of

significant figures: a. 25.5 mg to g b. 4.0 x 10-10 m to nm

c. 0.575 mm to m d. 0.076 L to mL

e. 1.55 kg/m3 to g/L f. 5.850 gal/hr to L/s. g 0.02500 ft3 to cm3 h. 62 °F to °C i. 216.7 °C to °F j. 2500 °F to K k. –246.1 °C to K

4. A cube of an unknown metal measures 1.61 mm on one side. The mass of the cube is 36 mg. Calculate the density of the metal in g/cm3. (Answer 8.63 g/cm3)

5. Gold can be hammered into extremely thin sheets called gold leaf. If a 200 mg piece of gold

(density = 19.32 g/cm3) is hammered into a sheet measuring 2.4 x 1.0 ft, what is the average thickness of the sheet in meters? How might the thickness be expressed without exponential notation, using an appropriate metric prefix? (4.6x10-8 m, 46 nm)

6. Two students conducted a laboratory exercise to determine the percentage of lead in a sample.

The true percentage is 3.55%. The students results in three trials are as follows: Student A: 3.20, 3.15, 3.22 Student B: 3.65, 3.58, 3.45 a. calculate the average percentage for each set of data and determine which set is more

accurate based on the average. (A: 3.19%, B: 3.55%, B is more accurate) b. Precision can be judged from the average deviation value. Using this value, determine

which set of data is more precise. (Set A = 0.03 – lower value, more precise, Set B = 0.08) 7. What is the number of significant figures in each of the following measurements:

a. 1282 kg b. 0.00296 s c. 0.0029600 s d. 8.070 mm e. 0.0105 L f. 9.7750 x 10-4 cm g. 5.000 cm h. 204.080 g i. 5.4040 x 102 km j. 143,700

8. Carry out the following operations, and express the answers with the appropriate number of

significant figures: a. 21.2405 + 5.80 b. 13.577 – 21.6 c. (5.03 x 10-4)(3.6675) d. 0.05770 75.3 e. (0.0045 x 20,000.0) + (2813 x 12) f. 863 x [1255 – (3.45 x 108)] g. [(285.3 x 105) – (1.200 x 103)] x 2.8954

2

9. An individual suffering from a high cholesterol level in her blood has 232 mg of cholesterol per 100 mL of blood. If the total blood volume of the individual is 5.2 L, how many grams of total blood cholesterol does the individual contain? (12 g cholesterol)

10. Give the definition for the following terms:

a. Atomic number (Z) b. Mass number (A) c. Isotopes d. Molecular formula e. Empirical formula f. Atomic weight. g. Metalloids

11. Fill in the blanks with the correct values.

SYMBOL NO. PROTON ( Z) NO. NEUTRON NO. ELECTRON MASS NO. (A)

Cr

33 42 33

20 20 20

86 86 222

77 77 193

O2- 16

Al3+ 27

K+ 39

Cl- 35

Na+ 23

Br- 80

Ca2+ 40

S2- 32

Fe3+ 56

12. Provide the correct names or formulae for the given compounds.

Name Chemical formula

(a) Copper(II) perchlorate

(b) Iron(III) carbonate

(c) CrCl3

(d) Calcium hydrogen carbonate

(e) H2SO4

(f) Sulfurous acid

(g) HBrO3

(h) HBr

(i) H3PO4

(j) Co(NO3)3

(k) CuSO4.5H2O

(l) Vanadium(III) bromide

(m) Hydrogen cyanide

(n) Tetraphosphorous hexasulfide