Q: Convert 0.025 kilometers to meters using dimensional analysis.

$$0.025\ km \times \frac{1000\ m}{1\ km} = 25\ m$$

Q: A nurse needs to convert 250 mL to microliters ($$\muL) $$for a medication dosage. What is the correct conversion?

$$250\ mL \times \frac{1,000\ \mu L}{1\ mL} = 250,000\ \mu L$$

Q: Which of the following is the correct way to round the result of $$3.4567 \times 2.1 to $$the correct number of significant figures?

$$3.4567 \times 2.1 = 7.3 ($$rounded to 2 significant figures)

Q: A medication is prescribed as 0.250 g. How many milligrams (mg) is this?

$$0.250\ g \times \frac{1,000\ mg}{1\ g} = 250\ mg$$

Question 1

Which of the following statements best describes the difference between the metric and English systems of measurement?

Accepted Answer

The metric system uses a base unit for each measurement type and conversion factors are powers of 10, while the English system uses arbitrary conversion factors between units.

Question 2

A graduated cylinder contains 25.0 mL of water. After adding a piece of metal, the water level rises to 32.5 mL. If the mass of the metal is 19.6 g, what is its density?

Accepted Answer

$$d = \frac{19.6\ g}{7.5\ mL} = 2.61\ g/mL$$

Question 3

Which of the following is the correct scientific notation for the number 0.000482?

Accepted Answer

$$4.82 	imes 10$$^{-4}$$

Question 4

A patient’s temperature is measured as $$102.2^\circ F. $$What is this temperature in Celsius?

Accepted Answer

$$T_C = \frac{102.2 - 32}{1.8} = 39.0^\circ C$$

Question 5

Which of the following measurements contains three significant figures?

Accepted Answer

0.0405 g

Question 6

Convert 0.025 kilometers to meters using dimensional analysis.

Accepted Answer

$$0.025\ km 	imes \frac{1000\ m}{1\ km} = 25\ m$$

Question 7

Which of the following is NOT a correct metric conversion factor?

Accepted Answer

1 centimeter (cm) = 10 millimeters (mm)

Question 8

A student records the mass of a sample as 0.00450 g. How many significant figures are in this measurement?

Accepted Answer

3

Question 9

Which of the following best describes the concept of density?

Accepted Answer

Density is the ratio of mass to volume, $$d = \frac{m}{V}.$$

Question 10

A nurse needs to convert 250 mL to microliters ($$\muL) $$for a medication dosage. What is the correct conversion?

Accepted Answer

$$250\ mL 	imes \frac{1,000\ \mu L}{1\ mL} = 250,000\ \mu L$$

Question 11

Which of the following is the correct way to round the result of $$3.4567 	imes 2.1 to $$the correct number of significant figures?

Accepted Answer

$$3.4567 	imes 2.1 = 7.3 ($$rounded to 2 significant figures)

Question 12

A sample of gold has a mass of 38.6 g and a volume of 2.00 cm$$^3. $$What is its density?

Accepted Answer

$$d = \frac{38.6\ g}{2.00\ cm^3$} = 19.3\ g/cm^3$

Question 13

Which of the following is a correct temperature conversion from Celsius to Kelvin?

Accepted Answer

$$T_K = T_C + 273$$

Question 14

A medication is prescribed as 0.250 g. How many milligrams (mg) is this?

Accepted Answer

$$0.250\ g 	imes \frac{1,000\ mg}{1\ g} = 250\ mg$$

Question 15

Which of the following is the correct way to express 5,000,000 g in scientific notation?

Accepted Answer

$$5.0 	imes 10$$^{6}$$\ g$$

Question 16

A laboratory measurement is recorded as 0.0700 L. Which digit is the estimated (doubtful) digit?

Accepted Answer

The last zero (the third digit after the decimal)

Question 17

Which of the following is a correct conversion factor for length in the English system?

Accepted Answer

1 mile = 5,280 feet

Question 18

A student needs to convert 3.20 $$	imes 10$^4$$ miles to inches. Which sequence of conversion factors should be used?

Accepted Answer

$$3.20 	imes 10^4$\ mi 	imes \frac{5280\ ft}{1\ mi} 	imes \frac{12\ in}{1\ ft}$$

Question 19

Which of the following best explains why significant figures are important in scientific measurements?

Accepted Answer

They indicate the precision of a measurement and help communicate the uncertainty in the value.

Chemistry and Measurements: Study Notes for GOB Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard