Chemistry 12

Unit 1 ~ Learning Guide Name: ___________KEY______________

Instructions:
Using a pencil, complete the following notes as you work through the related lessons. Show ALL
work as is explained in the lessons. You are required to have this package completed BEFORE
you write your unit test. Do your best and ask questions if you don’t understand anything! Some
questions have hints at the end of the learning guide. Try questions on your own before using
them.
Please print out the Formula Sheet and found at the start of the course. You will need this
to do assignments and tests!

Math in Science (review):

Measurements:
1. Why might scientists want to use metric measurements instead of Imperial measurements?

There was no consistent measurement system with Imperial measurements (just look at conversions
between inches, feet, yards and miles) With metric measurements, you have root units (eg. Metres
for distance, grams for mass, etc). Then you have a prefix that represents a specific power of 10.

2. What are base units for:

a) Mass: grams (g) b) Distance: metres (m)

c) Try finding this one online: Volume: Litres (L) or metres cubed (m3)

For specific prefixes, the involve a power of 10 or moving a decimal left or right.

Reminder: k h da ___ d c m

3. What does the ____ represent (or what do you put there)? The root unit
4. If I give you kg, what is the root unit? Grams (g)
5. If I give you 6.3kg and want to get ? g, what would your answer be? Grams (g) is 3 steps
right from k…so move the decimal 3 steps right 6.3kg -> 6300.g (3 steps is like multiplying by
103

Practice:
10 mm
6. 3.2cm = ? mm 32mm 3.2 cm× =32mm
1cm

1m 1 km −5
7. 3.2cm = ? km 3.2x10-5km 3.2 cm× × =3.2 ×10 km
100 cm 1000 m

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1g
8. 40cg = ? g 0.4g 40 cg × =0.4 g
100 cg

1000 g 1000 mg 6
9. 1.3kg = ? mg 1.3x106mg 1.3 kg × × =1.3 ×10
1 kg 1g

Scientific Notation:
10. Based on what you saw and read in this lesson, why might you want to use scientific notation?

Very large or very small numbers are challenging to work with. Scientific notation is a form of
shorthand notation making these numbers easier to work with and less prone to error when you write
them out or put them into your calculator

11. What is the format of Scientific Notation (include an example):

You have a number from 1 to less than 10 multiplied by 10 with an exponent

Eg. Convert to Scientific Notation

12. 5972000000000000000000000 kg 5.972 x 1024 kg (mass of the earth)

13. 0.0000000000000000000000000000009109 kg 9.109 x 10-31 kg (mass of an electron)

14. 6371000 m 6.371 x 106 m (radius of the earth)

15. 0.000025 m 2.5x10-5 m (diameter of a human hair)

Try math with scientific notation using your calculator:

16. 4.37 x 105 x 3.21 x 104 = 1.40 x 1010

17. 3.44 x 1024 / (6.02 x 1023) = 5.71

Significant Figures Rules:

18. What are the 5 rules for significant figures?

1. Non-zero numbers (1,2,3,4,5,6,7,8,9) are significant. (3.14 -> 3 sig figs)

2. Zeroes between non-zero numbers are significant. (300.104 -> 6 sig figs)
3. Following zeros to the right of non-zero numbers without a decimal are not sigficant.
With a decimal, they become significant. (200 -> 1 sig fig, 200. -> 3 sig figs)
4. Following zeroes which are to the right of the decimal point and following non-zero
numbers are significant, even at the end. (7.0300 -> 5 sig figs)
5. A zero used to show a decimal point (ie. a zero by itself on the left side of a decimal) is
not significant. All zeros between a decimal and the first non-zero numbers are not
significant.

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Using the 5 rules, complete the following table. NOTE: If you struggle with any of these, write your
question or confusion in the QUESTION column and check in with your teacher for clarification.

Eg. # sig figs Rule(s) used Sci Notation Questions?

37 2 1 3.7x101
6.92 3 1 6.92x100 (or
same)
670 2 1, 3 6.7x102
5000 1 1, 3 5x103
4000. 4 1, 3 4.000x103
65.0 3 1, 4 6.50x101
30.0020 6 1, 2, 4 3.00020x101
0.004 1 1, 5 4x10-3
6.00x10-2 3 1, 4 same

Significant Figures:
Complete each calculation ending with the correct number of significant figures

19. A chemist cuts a 13.25cm strip of magnesium to use only 5.8cm of it. What length of magnesium
remains?

13.25cm

- 5.8 cm This rounds to 7.5 cm

7.45 cm

20. A rectangular block has the dimensions 3.2cm x 4.71cm x 12cm. What is the volume of the block?

3.2cm x 4.71cm x 12cm = 180.864cm3 = 180cm3 (2 sig figs)

21. A rectangular garden plot has sides of length 13.21m and 6.10m. What is the area covered by this
plot?

13.21m x 6.10m = 80.581m2 = 80.6m2 (3 sig figs)

Dimensional Analysis & Unit Conversions

22. Convert 28.6 seconds to hours?

1 min 1 hr −3
28.6 seconds× × =0.00794 hours∨7.94 ×10 hours
60 seconds 60 min

23. Convert 600min to days

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1hour 1 day
600 min × × =0.4 days
60 min 24 hours

24. Convert 7 m/s to km/hr

m 1 km 60 s 60 min
7 × × × =25.2 km/hr 30 m/ s(1 sig fig)
s 1000 m 1 min 1 hr

Reaction Rates:

25. What is the definition of a reaction rate?

Reaction rate is defined as the rate of appearance of a product or the rate of disappearance
of a reactant.

26. For each of the following write i) a balanced chemical formula equation, ii) a complete ionic
equation and iii) a net ionic equation.

a) Magnesium metal is placed in a solution of hydrochloric acid and reacts to form aqueous
magnesium chloride and hydrogen gas

i) Mg(s) + 2 HCl(aq)  MgCl2(aq) + H2(g)

ii) Mg(s) + 2 H+(aq) + 2 Cl-(aq)  Mg2+(aq) + 2 Cl-(aq) + H2(g)
iii) Mg(s) + 2 H+(aq)  Mg2+(aq) + H2(g)

b) Aqueous chlorine is added to a solution of aluminum bromide in a single replacement reaction

which forms no precipitate and bromine liquid.

i) 3 Cl2(aq) + 2 AlBr3(aq)  2 AlCl3(aq) + 3 Br2(l)

ii) 3Cl2(aq) + 2Al3+(aq) + 6Br-(aq)  2Al3+(aq) + 6Cl-(aq) + 3Br2(l)
iii) 3 Cl2(aq) + 6 Br-(aq)  6 Cl-(aq) + 3 Br2(l)
27. For the following questions use the reaction in question 2a)

a) There are five possible rate equations that could be used to measure the reaction rate. Write
two of these possible rate equations.

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∆ mass of Mg ∆ pH
Rate= Rate=∆ ¿ ¿ Rate=
∆ Time ∆ Time

∆ volume H 2
Rate= Rate=∆ ¿ ¿
∆ Time

Students should write 2 of the above equations

b) What is the spectator ion for this reaction?

Cl-(aq)

c) If 0.0586 L of hydrogen gas is collected in 5.00 minutes, calculate the rate of the reaction in
mL of hydrogen gas per second.

1000 mL
0.0586 L x
∆ volume H 2 L 58.6 mL
Rate= = =
∆ Time 60 s 300. s
5 min x
1 min
Rate=0.195 mL H 2 / s

d) Using the reaction rate you calculated above, calculate the volume of hydrogen as produced in
23.0 minutes.

60 s 0.195 mL H 2
23.0 min x x =269 mL H 2
1 min 1s

e) Using the reaction rate you calculated above, calculate how long in minutes it takes to produce
1.50 L H2.

1000 mL 1s 1 min
1.50 L H 2 x x x =128 min
1L 0.195 mL H 2 60 s

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28.Use the reaction below to answer the following questions.

2 Ag(s) + Zn(NO3)2(aq)  Zn(s) + 2 Ag(NO3)(aq)

a) It is found that the rate of production of Zn(s) is 10.7 g/s. Calculate the mass of silver (in kg)
reacted in 15.2 minutes.

60 s 10.7 g Zn 1 mol Zn 2 mol Ag 107.9 g Ag 1 kg Ag

15.2 min x x x x x x
1min 1s 65.4 g Zn 1 mol Zn 1 mol Ag 1000 g Ag

¿ 32.2 kg Ag

b) If 14.3g of silver is used up in 5.0 minutes, what mass of zinc (in g) is formed in 45 seconds?

1 min 14.3 g Ag 1 mol Ag 1 mol Zn 65.4 g Zn

45 s x x x x x =¿0.65g Zn
60 s 5 min 107.9 g Ag 2 mol Ag 1mol Zn

29. What is the rate of reaction at 20 seconds? You will need to draw a tangent line. It can be tricky
to draw a perfect tangent line so don't worry if your answer does not exactly match the answer
key.

80

70

60

50

Mass40
(g)
30

20

10

0
0 20 40 Time (s) 60 80 100 120

0 g−45 g −45 g
Rate=Slope= = =−0.9 g /s
50 s−0 s 50 s

30.What are four factors that affect a reaction rate?

Nature of reactants, concentration, temperature, presence of catalyst or pressure

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31. List five ways you can increase the reaction rate of the reaction below.

6 Mg(s) + 1 N2(g) ® 2 Mg3N(s)

1. Increase the temperature

2. Add a catalyst

3. Increase the surface area of Mg

4. Increase [N2]

5. Increase pressure by decreasing the volume

32.Is the reaction in question 7 homogeneous or heterogeneous and how do you know?

Heterogeneous because there are two phases, gas and solid.

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Reaction Rates Hints:

2ai) Mg(s) + 2 HCl(aq)  MgCl2(aq) + H2(g)

2aii) If a compound is ionic you split it into its ions. If it is not you leave it as is.

2aiii) Remove any ions that are on both sides of the arrow (spectators)

mL
¿¿ x
∆ volume H 2 L
3c) Rate= = =¿
∆ Time s
¿ ¿ min x
¿¿ min

s mL H 2
3d) ¿¿ min x x =¿
¿ ¿ min ¿¿ s

mL s min
3e) ¿¿ L H 2 x x x =¿
¿ ¿ L ¿¿ mL H 2 ¿¿ s

s g Zn mol Zn mol Ag g Ag kg Ag
4a) ¿min x ¿ x x x x x =
min ¿¿ s ¿ ¿ g Zn ¿ ¿ mol Zn ¿mol Ag ¿ ¿ g Ag

min g Ag mol Ag mol Zn g Zn

4b) ¿¿ s x x x x x =¿
¿¿ s ¿¿ min ¿¿ g Ag ¿¿ mol Ag ¿ ¿ mol Zn

5) The rate is the slope and the slope is rise / run.

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