Question 1

Which of the following best describes the change that occurs when dry ice (solid CO$$_2) $$sublimes into gaseous CO$$_2 as $$shown in the images above?

Accepted Answer

A physical change, because the CO$$_2$$ molecules remain unchanged.

Question 2

A student measures the mass of a coin as shown in the image above. If the balance reads 5.01 g, how many significant figures should be reported for this measurement?

Accepted Answer

3

Question 3

Which of the following is an example of a heterogeneous mixture, as illustrated in the images above?

Accepted Answer

Granite rock

Question 4

A chemist finds that 25.00 cm$$^3 of an $$unknown liquid has a mass of 19.625 g at 20$$^	ext{o}C. $$Using the table of densities provided, identify the liquid.

Accepted Answer

Ethanol

Question 5

Which of the following best describes the process of sugar dissolving in water, as shown in the images above?

Accepted Answer

A physical change, because the chemical composition of sugar remains unchanged.

Question 6

Convert 381 grams to pounds. (1 lb = 454 g)

Accepted Answer

$$0.840 lb$$

Question 7

A 747 is fueled with 173,231 L of jet fuel. If the density of the fuel is $$0.768 \ \mathrm{g/cm^3$}$$, what is the mass of the fuel in kilograms?

Accepted Answer

$$133,100 kg$$

Question 8

Which of the following is an intensive property?

Accepted Answer

Density

Question 9

A solution is prepared by dissolving 1.935 g of sodium chloride in 215.0 g of water. What is the total mass of the solution, reported with the correct number of significant figures?

Accepted Answer

$$216.9 g$$

Question 10

Which of the following best describes the difference between accuracy and precision, as illustrated in the bar graph image above?

Accepted Answer

Accuracy is how close measurements are to the true value; precision is how close measurements are to each other.

Question 11

A student adds $$12.5 + 3.269 - 5.12. $$What is the answer, rounded to the correct number of decimal places?

Accepted Answer

$$10.6$$

Question 12

Which of the following is the correct scientific notation for the number 0.00051274 with three significant figures?

Accepted Answer

$$5.13 	imes 10$$^{-4}$$

Question 13

A runner covers 7.5 km at a pace of 65 meters per minute. How many minutes does it take to complete the distance?

Accepted Answer

$$115$$ min

Question 14

Which of the following is the correct conversion factor to convert from square inches to square centimeters?

Accepted Answer

$$1 \ \mathrm{in}^2 = 6.45 \ \mathrm{cm}^2$$

Question 15

A buret is filled to the zero mark and dispenses solution to the 22.00 mL mark. What volume should be reported, based on the image above?

Accepted Answer

$$22.0 mL$$

Question 16

Which of the following is the correct relationship between Celsius and Kelvin temperatures?

Accepted Answer

$$K = ^\circ C + 273.15$$

Question 17

A solution contains 30.00% potassium iodide salt by mass. How many grams of potassium iodide salt are in 40.0 g of solution?

Accepted Answer

$$12.0 g$$

Question 18

Which of the following is a derived SI unit?

Accepted Answer

Liter

Question 19

Which of the following best describes the change that occurs when propane gas burns, as shown in the images above?

Accepted Answer

A chemical change, because new substances are formed.

Question 20

If a sample of water is decomposed into hydrogen and oxygen, and the mass of hydrogen formed is always about 1/9 the mass of water, which law does this illustrate?

Accepted Answer

Law of Definite Proportions

Chapter 1: Matter, Measurement, and Problem Solving – General Chemistry Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard