Q: A hospital has 125 deciliter (dL) bags of blood plasma. What is the volume expressed in milliliters (mL)?

$$1.25 \times 10^4$ mL$$\ (125\ dL \times \frac{$$10^2$$\ mL}{1\ dL} = 1.25 \times $$10^4$$\ mL)$$

Q: A foundation for a new house measures 14 m long, 15 cm thick, and has a total volume of 23.1 m$$^3. $$What is the width of the home? (First, convert 15 cm to meters.)

$$w = \frac{23.1}{14 \times 0.15} = 11 m$$

Q: If a dog weighs 1000.0 g, what is his weight in ounces? (1 pound = 16 ounces, 1 kilogram = 2.2 pounds)

$$1000.0\ g \times \frac{1\ kg}{1000\ g} \times \frac{2.2\ lb}{1\ kg} \times \frac{16\ oz}{1\ lb} = 35.2\ oz$$

Q: A marathon is 26.2 miles. How many inches are in a marathon? (1 mile = 5,280 feet, 1 foot = 12 inches)

$$26.2 \times 5280 \times 12 = 1,658,496$$ inches

Q: If a 14-karat ring contains 20.0 g of gold and 14.3 g of silver, what is the percent gold in the ring?

$$\frac{20.0}{20.0 + 14.3} \times 100 = 58.3\%$$

Question 1

Which of the following statements best describes the difference between measured and exact numbers?

Accepted Answer

Measured numbers have uncertainty and are obtained using instruments, while exact numbers are counted and have no uncertainty.

Question 2

A student measures the volume of a liquid in a graduated cylinder and records 19.257 mL. Which digit is uncertain in this measurement?

Accepted Answer

The digit 7

Question 3

Which of the following best illustrates the concept of accuracy in measurement?

Accepted Answer

Three measurements of 4.25 cm when the true value is 4.25 cm

Question 4

A hospital has 125 deciliter (dL) bags of blood plasma. What is the volume expressed in milliliters (mL)?

Accepted Answer

$$1.25 	imes 10^4$ mL$$\ (125\ dL 	imes \frac{$$10^2$$\ mL}{1\ dL} = 1.25 	imes $$10^4$$\ mL)$$

Question 5

Which of the following numbers has four significant figures?

Accepted Answer

0.03070

Question 6

Convert 0.00034 to scientific notation.

Accepted Answer

$$3.4 	imes 10$$^{-4}$$

Question 7

A cube of silver is 5.00 cm on a side and has a density of 10.5 g/cm$$^3. $$What is the mass of the silver?

Accepted Answer

$$1.31 	imes 10^3$ g

Question 8

Which of the following is an exact equivalent and has an infinite number of significant figures?

Accepted Answer

1 quart = 32 ounces

Question 9

A foundation for a new house measures 14 m long, 15 cm thick, and has a total volume of 23.1 m$$^3. $$What is the width of the home? (First, convert 15 cm to meters.)

Accepted Answer

$$w = \frac{23.1}{14 	imes 0.15} = 11 m$$

Question 10

Which of the following is the correct way to round 7.426 to two significant figures?

Accepted Answer

7.43

Question 11

If a dog weighs 1000.0 g, what is his weight in ounces? (1 pound = 16 ounces, 1 kilogram = 2.2 pounds)

Accepted Answer

$$1000.0\ g 	imes \frac{1\ kg}{1000\ g} 	imes \frac{2.2\ lb}{1\ kg} 	imes \frac{16\ oz}{1\ lb} = 35.2\ oz$$

Question 12

Which of the following best describes the density of an object that floats in water?

Accepted Answer

The density is less than 1.00 g/mL.

Question 13

A marathon is 26.2 miles. How many inches are in a marathon? (1 mile = 5,280 feet, 1 foot = 12 inches)

Accepted Answer

$$26.2 	imes 5280 	imes 12 = 1,658,496$$ inches

Question 14

Which of the following is the correct number of significant figures for the value 0.0000504 L?

Accepted Answer

3

Question 15

Which metric prefix represents $$10^{-6}$$?

Accepted Answer

micro (\mu)

Question 16

A platinum sample has a mass of 224.50 g and a volume of 10.0 cm$$^3. $$What is its density?

Accepted Answer

$$22.5\ g/cm^3$

Question 17

Which of the following is the correct answer for $$(4.273 \div 1.2)$$ with the correct number of significant figures?

Accepted Answer

$$3.56$$

Question 18

Which of the following is the correct way to express 2500 g with two significant figures in scientific notation?

Accepted Answer

$$2.5 	imes 10^3$ g

Question 19

If a 14-karat ring contains 20.0 g of gold and 14.3 g of silver, what is the percent gold in the ring?

Accepted Answer

$$\frac{20.0}{20.0 + 14.3} 	imes 100 = 58.3\%$$

Measurement and Problem Solving: Structured Study Notes for Introductory Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard