Question 1

Classify the following properties of hydrogen gas as either intensive or extensive.
a. the mass of the gas sample
b. the average speed of a molecule in the sample
c. temperature
d. density
e. number of molecules present

Accepted Answer

The answer of Classify the following properties of hydrogen gas...

Question 2

Which one of the following numbers contains a digit or digits which is/are not significant?
A) 970.0
B) 502
C) .300
D) .0043
E) 20.01

Accepted Answer

In the number .0043, the leading zeros are not significant. Only the digits 4 and 3 are significant.

Question 3

Which measurement is expressed to 4 significant figures?
A) 0.423 kg
B) 24.049 cm
C) 1300 K
D) 82,306 m
E) 62.40 g

Accepted Answer

The answer of Which measurement is expressed to 4 significant...

Question 4

The ripening of fruit, once picked, is an example of physical change.

Accepted Answer

The ripening of fruit involves chemical changes, including the conversion of starches to sugars, changes in color, and the breakdown of cell walls, which are not reversible and alter the chemical composition of the fruit.

Question 5

In each of the sets below, choose the one quantity or number which is exact. A) i. the human population ii. the distance in light years from the sun to Alpha Centauri, a nearby star iii. the winning time for the 100 m dash in the Olympic Games B) i. the weight of a particular one cent coin in g ii. the boiling point of lead, in °C iii. the number of cm in 1 yd C) i. the measured value of the speed of light (2.998 × 10⁸ m/s) ii. π (3.141) iii. the volume of milk in a 1-gallon jug

Accepted Answer

The answer of In each of the sets below, choose...

Question 6

An important aim in much chemical work is to use macroscopic measurements in order to gain an understanding of the microscopic world.

Accepted Answer

This statement is true. Many chemical experiments involve measuring macroscopic properties such as mass, volume, and temperature in order to gain insights into the behavior of microscopic particles such as atoms and molecules.

Question 7

Select the answer with the correct number of decimal places for the following sum: 13.914 cm + 243.1 cm + 12.00460 cm =
A) 269.01860 cm
B) 269.0186 cm
C) 269.019 cm
D) 269.02 cm
E) 269.0 cm

Accepted Answer

The answer of Select the answer with the correct number...

Question 8

Select the answer that expresses the result of this calculation with the correct number of significant figures and with correct units. 16.18 cm × 9.6114 g ÷ 1.4783 cm² = A) 105.2 g/cm³ B) 105.2 g/cm² C) 105.2 g/cm D) 72.13 g/cm² E) 72.13 g/cm

Accepted Answer

First, we need to simplify the calculation: 16.18 cm * 9.6114 g / 1.4783 cm² = 104.777 g/cm We have to round to three significant figures (the lowest number of significant figures in the calculation) and keep the unit of g/cm. Thus, the answer is 105.2 g/cm. Choice C is the only one that matches this answer.

Question 9

The difference between a student's experimental measurement of the density of sodium chloride and the known density of this compound reflects the ___________ of the student's result.
A) accuracy
B) precision
C) random error
D) systematic error
E) indeterminate error

Accepted Answer

The answer of The difference between a student's experimental measurement...

Question 10

Select the answer that expresses the result of this calculation with the correct number of significant figures. 
A) 13.3568
B) 13.357
C) 13.36
D) 13.4
E) 13

Accepted Answer

The answer of Select the answer that expresses the result...

Question 11

The result of (3.8621 × 1.5630) - 5.98 is properly written as
A) 0.06.
B) 0.056.
C) 0.0565.
D) 0.05646.
E) 0.056462.

Accepted Answer

The answer of The result of (3.8621 × 1.5630) -...

Question 12

The appropriate number of significant figures in the result of 15.234 - 15.208 is
A) 1.
B) 2.
C) 3.
D) 4.
E) 5.

Accepted Answer

15.234 and 15.208 both have three significant figures. When we subtract them, the result is 0.026. Since we are dealing with subtraction, we look at the number with the least number of decimal places, which in this case is 15.208 with one decimal place. Therefore, the answer should also have only one decimal place, so the appropriate number of significant figures is 2.

Question 13

As part of an experiment to determine the density of a new plastic developed in her laboratory, Sara Ann Dippity measures the volume of a solid sample. Her four trials yield volumes of 12.37 cm³, 12.41 cm³, 12.39 cm³, and 12.38 cm³. Measurements of other scientists in the lab give an average volume of 12.49 cm³. Which of the following statements represents the best analysis of the data? A) Sara's results have low precision and high accuracy. B) Sara's results have high precision and high accuracy. C) Sara's results have greater precision than accuracy. D) Sara's results have greater accuracy than precision. E) Sara has been using a faulty instrument to measure the volume.

Accepted Answer

Sara's measurements have a small range (12.37-12.41), indicating high precision. However, her measurements do not match the average volume determined by other scientists, indicating low accuracy. Therefore, her results have greater precision than accuracy.

Question 14

The appropriate number of significant figures in the result of 15.234 × 15.208 is
A) 2.
B) 3.
C) 4.
D) 5.
E) 6.

Accepted Answer

The answer of The appropriate number of significant figures in...

Question 15

A student makes several measurements of the density of an unknown mineral sample. She then reports the average value of these measurements. The number of significant figures she uses in her result should be a measure of its
A) accuracy.
B) precision.
C) systematic error.
D) determinate error.
E) human error.

Accepted Answer

The number of significant figures used in the result indicates the precision of the measurement. It does not necessarily reflect the accuracy, or how close the measured value is to the true value. Using more significant figures can imply a higher level of precision, but it also requires a higher level of confidence in the accuracy of the measurement equipment and technique used.

Question 16

As chief chemist at Superior Analytical Products (SAP) you must design an experiment to determine the density of an unknown liquid to three (3) significant figures. The density is of the order of 1 g/cm³. You have approximately 7 mL of the liquid and only graduated cylinders and balances are available for your use. Which of the following combinations of equipment will allow you to meet but not exceed your goal? A) graduated cylinder with ±0.1 mL uncertainty; balance with ±0.1 g uncertainty B) graduated cylinder with ±0.01 mL uncertainty; balance with ±0.1 g uncertainty C) graduated cylinder with ±0.01 mL uncertainty; balance with ±0.01 g uncertainty D) graduated cylinder with ±0.001 mL uncertainty; balance with ±0.001 g uncertainty E) graduated cylinder with ±0.1 mL uncertainty; balance with ±0.001 g uncertainty

Accepted Answer

To determine density to three significant figures, both the volume and mass measurements must be precise enough. A graduated cylinder with ±0.01 mL uncertainty and a balance with ±0.01 g uncertainty will provide sufficient precision without exceeding the requirement.

Question 17

Bud N. Chemist must determine the density of a mineral sample. His four trials yield densities of 4.77 g/cm³, 4.67 g/cm³, 4.69 g/cm³, and 4.81 g/cm³. Independent studies found the correct density to be 4.75 g/cm³. Which of the following statements represents the best analysis of the data? A) Bud's results have much greater accuracy than precision. B) Bud's results have much greater precision than accuracy. C) Bud's results have high accuracy and high precision. D) Bud's results have low accuracy and low precision. E) Bud's equipment is faulty.

Accepted Answer

The answer of Bud N. Chemist must determine the density...

Question 18

Which of the following correctly expresses 52,030.2 m in scientific notation? A) 5.20302 × 10⁴ m B) 5.20302 × 10⁵ m C) 5.203 × 10⁴ m D) 5.20 × 10⁴ m E) 5.2 × 10⁴ m

Accepted Answer

The answer of Which of the following correctly expresses 52,030.2...

Question 19

Which of the following correctly expresses 0.000007913 g in scientific notation? A) 7.913 × 10⁶ g B) 7.913 × 10⁵ g C) 7.913 × 10^-5 g D) 7.913 × 10^-6 g E) 7.913 × 10^-9 g

Accepted Answer

To convert 0.000007913 g to scientific notation, we move the decimal point 6 places to the right and add a negative exponent, giving us 7.913 × 10^-6 g. Therefore, choice D is correct.

Question 20

Express 96,342 m using 2 significant figures. A) 9.60 × 10⁴ m B) 9.6 × 10⁴ m C) 9.60 × 10^-4 m D) 9.6 × 10^-4 m E) 96000. m

Accepted Answer

When expressing a number to 2 significant figures, we round off to the second digit unless the third digit is 5 or greater, in which case we round up. In this case, the third digit is 3, so we round down to 9.6. The rest of the digits are insignificant and can be expressed using scientific notation, so the answer is 9.6 × 10^4 m, which is option B.

Quiz 1: Keys to Studying Chemistry Definitions, Units, and Problem Solving

Classify the following properties of hydrogen gas as either intensive or extensive. a. the mass of the gas sample b. the average speed of a molecule in the sample c. temperature d. density e. number of molecules present

Which one of the following numbers contains a digit or digits which is/are not significant?

Which measurement is expressed to 4 significant figures?

The ripening of fruit, once picked, is an example of physical change.

An important aim in much chemical work is to use macroscopic measurements in order to gain an understanding of the microscopic world.

Select the answer with the correct number of decimal places for the following sum: 13.914 cm + 243.1 cm + 12.00460 cm =

Select the answer that expresses the result of this calculation with the correct number of significant figures and with correct units. 16.18 cm × 9.6114 g ÷ 1.4783 cm2 =

The difference between a student's experimental measurement of the density of sodium chloride and the known density of this compound reflects the ___________ of the student's result.

Select the answer that expresses the result of this calculation with the correct number of significant figures.

The result of (3.8621 × 1.5630) - 5.98 is properly written as

The appropriate number of significant figures in the result of 15.234 - 15.208 is

The appropriate number of significant figures in the result of 15.234 × 15.208 is

A student makes several measurements of the density of an unknown mineral sample. She then reports the average value of these measurements. The number of significant figures she uses in her result should be a measure of its

Bud N. Chemist must determine the density of a mineral sample. His four trials yield densities of 4.77 g/cm3, 4.67 g/cm3, 4.69 g/cm3, and 4.81 g/cm3. Independent studies found the correct density to be 4.75 g/cm3. Which of the following statements represents the best analysis of the data?

Which of the following correctly expresses 52,030.2 m in scientific notation?

Which of the following correctly expresses 0.000007913 g in scientific notation?

Express 96,342 m using 2 significant figures.

Select the answer that expresses the result of this calculation with the correct number of significant figures and with correct units. 16.18 cm × 9.6114 g ÷ 1.4783 cm² =

Bud N. Chemist must determine the density of a mineral sample. His four trials yield densities of 4.77 g/cm³, 4.67 g/cm³, 4.69 g/cm³, and 4.81 g/cm³. Independent studies found the correct density to be 4.75 g/cm³. Which of the following statements represents the best analysis of the data?