Q: Convert $$0.00056 to $$scientific notation and identify the number of significant figures.

$$5.6 \times 10$$^{-4}$$, 2 significant figures

Q: Convert $$5.0 \ \mathrm{km} to $$meters using unit analysis.

$$5.0 \times 10^3$ \ \mathrm{m}$$

Question 1

Which of the following is an example of an exact number?

Accepted Answer

The number of students in a classroom

Question 2

A student measures the length of a rod three times and gets values very close to each other, but far from the true value. This is an example of:

Accepted Answer

High precision, low accuracy

Question 3

Why do measured numbers always have uncertainty?

Accepted Answer

Because of limitations in the measuring instrument and human estimation

Question 4

Which of the following numbers has three significant figures?

Accepted Answer

$$0.0405$$

Question 5

Convert $$0.00056 to $$scientific notation and identify the number of significant figures.

Accepted Answer

$$5.6 	imes 10$$^{-4}$$, 2 significant figures

Question 6

Which of the following is the correct sum, with the correct number of significant figures, for $$12.11 + 0.034 + 1.3$$?

Accepted Answer

$$13.4$$

Question 7

Which of the following is NOT a base SI unit?

Accepted Answer

Gram (g)

Question 8

A block has a mass of $$250 \ \mathrm{g}$$ and a volume of $$50.0 \ \mathrm{cm}^3. $$What is its density?

Accepted Answer

$$5.0 \ \mathrm{g/cm}^3$$

Question 9

Convert $$5.0 \ \mathrm{km} to $$meters using unit analysis.

Accepted Answer

$$5.0 	imes 10^3$ \ \mathrm{m}$$

Question 10

Rearrange the equation $$d = \frac{m}{v} to $$solve for $$v.$$

Accepted Answer

$$v = \frac{m}{d}$$

Question 11

Which of the following is a correct conversion factor for converting liters to milliliters?

Accepted Answer

$$1 \ \mathrm{L} = 1000 \ \mathrm{mL}$$

Question 12

A student records the mass of a sample as $$12.340 \ \mathrm{g}. $$Which digit is the estimated digit?

Accepted Answer

The last digit, 0

Question 13

Which of the following numbers contains a captive zero?

Accepted Answer

$$205$$

Question 14

A graduated cylinder is read at the bottom of the meniscus. Why is this important?

Accepted Answer

It ensures the most accurate measurement of the liquid's volume.

Question 15

Which SI prefix represents $$10^{-3}$$?

Accepted Answer

Milli-

Question 16

A sample of ethanol has a density of $$0.789 \ \mathrm{g/mL}. $$What is the mass of $$25.0 \ \mathrm{mL} of $$ethanol?

Accepted Answer

$$19.7 \ \mathrm{g}$$

Question 17

Which of the following is the correct way to express $$0.000305 in $$scientific notation?

Accepted Answer

$$3.05 	imes 10$$^{-4}$$

Question 18

A student needs to convert $$250 \ \mathrm{mg} to $$grams. What is the correct answer?

Accepted Answer

$$0.250 \ \mathrm{g}$$

Question 19

Which of the following best describes a trailing zero?

Accepted Answer

A zero at the end of a number after a decimal point

Question 20

A student adds $$2.50 \ \mathrm{mL} of $$water to $$7.1 \ \mathrm{mL} of $$ethanol. What is the correct sum with the proper number of significant figures?

Accepted Answer

$$9.6 \ \mathrm{mL}$$

2: Numerical Side of Chemistry: Measurement, Units, and Problem Solving

Guida di studio - Domande di pratica

Study guide - Flashcard