Question 1

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

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 defines accuracy in a scientific measurement?

Accepted Answer

The closeness of a single measurement to its true value.

Question 4

A nail is measured three times with results: 4.10 cm, 4.10 cm, and 4.10 cm. The actual length is 4.25 cm. Which statement is correct?

Accepted Answer

The measurements are precise but not accurate.

Question 5

Which of the following numbers has 4 significant figures?

Accepted Answer

$$0.03070$$

Question 6

Express $$0.00034 in $$scientific notation.

Accepted Answer

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

Question 7

How many significant figures should be reported in the answer to $$4.273 \div 1.2$$?

Accepted Answer

2

Question 8

A hospital has $$125$$ deciliter bags of blood plasma. What is the total volume in milliliters?

Accepted Answer

$$12,500 mL$$

Question 9

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

$$1,310 g$$

Question 10

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

Accepted Answer

$$1$$ liter $$= 1000$$ milliliters

Question 11

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

$$11 m$$

Question 12

If a marathon is $$26.2$$ miles, how many inches are in the marathon? ($$1$$ mile $$= 5,280$$ feet, $$1$$ foot $$= 12$$ inches)

Accepted Answer

$$1,660,416$$ inches

Question 13

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

Accepted Answer

Its density is less than $$1.00 g/mL.$$

Question 14

A shed has a volume of $$326 ft$^3. $$Express this in m$$^3$$. ($$1 in$$ $$= 2.54 cm$$, $$1 ft$$ $$= 12 in$$, $$1 m$$ $$= 100 cm)$$

Accepted Answer

$$9.23 m$^3$$

Question 15

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

Accepted Answer

micro-

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

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

$$58.3\%$$

Question 18

Which of the following is the correct answer for $$(15.6 	imes 4.0) + 225.634$$ with the correct number of significant figures?

Accepted Answer

$$288$$

Question 19

Which of the following is the correct way to report the product $$(3.75 	imes 10$$^{15}$$) 	imes (8.605 	imes 10$$^{4}$$)$$ with the correct number of significant figures?

Accepted Answer

$$3.23 	imes 10$$^{20}$$

Measurement and Problem Solving in Chemistry

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