MODULE 2

Question 1

Avogadro’s number

Answer 1

6.022 x 10^23 particles

Question 2

is the number of digits known exactly plus one digit whose value is uncertain

Answer 2

SIGNIFICANT FIGURES

Question 3

How many significant figures?
(a) 0.0120 mol HCl

Answer 3

Three significant figures; 1.20×10–2 mol HCl

Question 4

How many significant figures?
(b) 605.3 mg CaCO3

Answer 4

(b) Four significant figures; 6.053×102
mg CaCO3

Question 5

How many significant figures?
(c) 1.043×10–4 mol Ag+

Answer 5

(c) Four significant figures; 0.000 104 3 mol Ag+

Question 6

How many significant figures?
(d) 9.3×104 mg NaOH

Answer 6

(d) Two significant figures; 93 000 mg NaOH

Question 7

a general measurement unit that reports the amount of solute present in a known amount of solution

Answer 7

CONCENTRATION

Question 8

the concentration of a particular chemical species

Answer 8

MOLARITY

Question 9

is a substance’s total concentration without regard to its specific chemical form

Answer 9

FORMALITY

Question 10

Moles solute/ Liters solution

Answer 10

Molarity (M)

Question 11

grams solute / 100 grams solution

Answer 11

weight percent %w/w

Question 12

mL solute/ 100 mL solution

Answer 12

volume percent %v/v

Question 13

grams solute/ 100 mL solution

Answer 13

weight-volume percent %w/v

Question 14

grams solute/ 10^6 grams solution

Answer 14

ppm

Question 15

grams solute/ 10^9 grams solution

Answer 15

ppb

Question 16

TRUE OR FALSE: Physical units only allow the first uncertain number

Answer 16

TRUE

Question 17

HOW MANY SIGNIFICANT FIGURES?
246.320

Answer 17

6; Zeros at the end of a number with decimal point are significant

Question 18

HOW MANY SIGNIFICANT FIGURES?
1.008

Answer 18

4; ZEROES between non-zero are significant

Question 19

HOW MANY SIGNIFICANT FIGURES?
0.00340

Answer 19

3

Question 20

HOW MANY SIGNIFICANT FIGURES?
100.3

Answer 20

3

Question 21

HOW MANY SIGNIFICANT FIGURES?

0.0001

Answer 21

1

Question 22

HOW MANY SIGNIFICANT FIGURES?

350.670

Answer 22

6

Question 23

HOW MANY SIGNIFICANT FIGURES?

1.0000

Answer 23

5

Question 24

700000

Answer 24

1

Question 25

Calculate the answers to the appropriate number of significant figures. 658.0+ 23.5478 + 1345.29

Answer 25

2026.8

Question 26

Calculate the answers to the appropriate number of significant figures. 246.24 +238.278 + 98.3

Answer 26

582.8

Question 27

Calculate the answers to the appropriate number of significant figures. 32.567 +135.0 + 1.4567

Answer 27

169.0

Question 28

Calculate the answers to the appropriate number of significant figures. 23.7 x 3.8

Answer 28

90.

Question 29

Calculate the answers to the appropriate number of significant figures. 45.76 x 0.25

Answer 29

11

Question 30

Calculate the answers to the appropriate number of significant figures. 81.04 g x0.010

Answer 30

0.81

Question 31

Calculate the answers to the appropriate number of significant figures. 6.47 x 64.5

Answer 31

417

Question 32

Calculate the answers to the appropriate number of significant figures. 43.678 x 64.1

Answer 32

2.80 x 10^3

Question 33

Calculate the answers to the appropriate number of significant figures. 1.678 / 0.42

Answer 33

4.0

Question 34

Calculate the answers to the appropriate number of significant figures. 28.367 / 3.74

Answer 34

7.58

Question 35

Calculate the answers to the appropriate number of significant figures. 4278 / 1.006

Answer 35

4252