Unit 1 Pre-AP Chemistry Test| Updated New
Jen measured the density of a dice cube as 6.54 g/cm3, but her teacher revealed the density as
7.12 g/cm3
What is the percent error?
(Value of Accepted - Value of Measured) / Value of Accepted = answer +mes 100
6.54 g/cm3 - Measured
7.12 g/cm3 - Accepted
1. 7.12 - 6.54 = 0.58
2. 0.58
3. 0.58/7.12 = 0.08146067
4. 0.08146067 x 100 = 8.146067
5. 8.15% (Significant figures)
The mass of a sheet of paper is 130 grams. The volume of the sheet of paper is 12.34 cm3. What
is the density?
Mass/Volume
130/12.34 = 10.534846
11g/cm3 (Significant figures)
The mass of an object is 275 grams and the density is 25.0g/cm3. What is the volume?
275/25.0 = 11.0 cm3
275/y (volume) x 25.0/1 (cross mul+ply as frac+ons)
25.0y = 275
y = 275/25.0 = 11.0
y = 11.0
11.0 cm3
The volume of an object is 40 cm3 and the density is 20g/cm3. What is the mass?
40 x 20 = 800
800g/40 cm3 = 20g/cm3
800 grams
Significant Figures Equa+ons:
1. 1.203 + 2.09
, 2. 6.55 - 1.773
3. 11.4 x 10
4. 9.0/6.57
1. 3.29 (3.293)
2. 4.78 (4.777)
3. 100 (114)
4. 1.4 (1.36986)
Scien+fic Nota+on: (the numbers beside the tens are exponents)
1. (6.7 x 105) + (2.3 x 103)
2. (4.5 x 10-2) - (9.8 x 10-4)
3. (3.3 x 10-5) x (5.6 x 10-9)
4. (5.6 x 109) / (3.4 x 106)
1. 6.723 x 105 (6.7, decimal places)
2. 4.402 x 10-2 (4.4, decimal places)
3. 1.848 x 10-13 (1.8, significant figures)
4. 1.647 x 103 (1.6, significant figures)
Dimensional Analysis: Convert 21100 mm to miles.
21100 mm/1 x 1 cm/10 mm x 1 inch/2.54 cm x 1 foot/12 inches x 1 mile/5280 = = 0.01311 mile
0.0131 mile (Significant figures)
Dimensional Analysis: Convert 908 g/cm3 to lb/in3
908 g/cm3 x 1 lb/454 g x 2.54 cm3/in3 =
5.08 lb/in3
What is the difference between qualita+ve and quan+ta+ve data?
1. Qualita+ve - Data that requires descrip+on (narra+ve)
2. Quan+ta+ve - Data that requires numbers
What is the SI System?
What is the difference between accuracy and precision?
Accuracy - conforming to the correct value or standard
Precision - ability to generate the same value repeatedly
What are the three main separa+on methods and what how do they work?
Jen measured the density of a dice cube as 6.54 g/cm3, but her teacher revealed the density as
7.12 g/cm3
What is the percent error?
(Value of Accepted - Value of Measured) / Value of Accepted = answer +mes 100
6.54 g/cm3 - Measured
7.12 g/cm3 - Accepted
1. 7.12 - 6.54 = 0.58
2. 0.58
3. 0.58/7.12 = 0.08146067
4. 0.08146067 x 100 = 8.146067
5. 8.15% (Significant figures)
The mass of a sheet of paper is 130 grams. The volume of the sheet of paper is 12.34 cm3. What
is the density?
Mass/Volume
130/12.34 = 10.534846
11g/cm3 (Significant figures)
The mass of an object is 275 grams and the density is 25.0g/cm3. What is the volume?
275/25.0 = 11.0 cm3
275/y (volume) x 25.0/1 (cross mul+ply as frac+ons)
25.0y = 275
y = 275/25.0 = 11.0
y = 11.0
11.0 cm3
The volume of an object is 40 cm3 and the density is 20g/cm3. What is the mass?
40 x 20 = 800
800g/40 cm3 = 20g/cm3
800 grams
Significant Figures Equa+ons:
1. 1.203 + 2.09
, 2. 6.55 - 1.773
3. 11.4 x 10
4. 9.0/6.57
1. 3.29 (3.293)
2. 4.78 (4.777)
3. 100 (114)
4. 1.4 (1.36986)
Scien+fic Nota+on: (the numbers beside the tens are exponents)
1. (6.7 x 105) + (2.3 x 103)
2. (4.5 x 10-2) - (9.8 x 10-4)
3. (3.3 x 10-5) x (5.6 x 10-9)
4. (5.6 x 109) / (3.4 x 106)
1. 6.723 x 105 (6.7, decimal places)
2. 4.402 x 10-2 (4.4, decimal places)
3. 1.848 x 10-13 (1.8, significant figures)
4. 1.647 x 103 (1.6, significant figures)
Dimensional Analysis: Convert 21100 mm to miles.
21100 mm/1 x 1 cm/10 mm x 1 inch/2.54 cm x 1 foot/12 inches x 1 mile/5280 = = 0.01311 mile
0.0131 mile (Significant figures)
Dimensional Analysis: Convert 908 g/cm3 to lb/in3
908 g/cm3 x 1 lb/454 g x 2.54 cm3/in3 =
5.08 lb/in3
What is the difference between qualita+ve and quan+ta+ve data?
1. Qualita+ve - Data that requires descrip+on (narra+ve)
2. Quan+ta+ve - Data that requires numbers
What is the SI System?
What is the difference between accuracy and precision?
Accuracy - conforming to the correct value or standard
Precision - ability to generate the same value repeatedly
What are the three main separa+on methods and what how do they work?
