Q: Which of the following is the correct value for Avogadro's number, $N_A$, as given in the provided materials?

$6.022 \times 10^{23}\ \text{mol}^{-1}$

Q: A student needs to convert $15\ \text{km}$ to meters. Which of the following is the correct conversion factor and answer?

Multiply by $1000$; $15\ \text{km} \times 1000 = 15,000\ \text{m}$

Q: If you have $100.0\ \text{mol}$ of Fe, how many atoms of Fe do you have? (Use $N_A = 6.022 \times 10^{23}\ \text{mol}^{-1}$)

$100.0 \times 6.022 \times 10^{23} = 6.022 \times 10^{25}$ atoms

Q: Which of the following correctly converts $20\ \text{m/s}$ to $\text{km/hr}$?

$20\ \text{m/s} \times \frac{1\ \text{km}}{1000\ \text{m}} \times \frac{3600\ \text{s}}{1\ \text{hr}} = 72\ \text{km/hr}$

Q: Which of the following is the correct conversion for $1\ \text{in} = 2.54\ \text{cm}$?

$1\ \text{in} = 2.54\ \text{cm}$

Q: Which of the following is the correct way to express $0.000232\ \text{L}$ in scientific notation?

$2.32 \times 10^{-4}\ \text{L}$

Q: A student is asked to convert $15\ \text{km}$ to miles. Which conversion factor should they use?

$1\ \text{mi} = 1.609\ \text{km}$

Question 1

Which of the following is the correct value for Avogadro's number, $N_A$, as given in the provided materials?

Accepted Answer

$6.022 	imes 10^{23}\ 	ext{mol}^{-1}$

Question 2

A student needs to convert $15\ 	ext{km}$ to meters. Which of the following is the correct conversion factor and answer?

Accepted Answer

Multiply by $1000$; $15\ 	ext{km} 	imes 1000 = 15,000\ 	ext{m}$

Question 3

If you have $100.0\ 	ext{mol}$ of Fe, how many atoms of Fe do you have? (Use $N_A = 6.022 	imes 10^{23}\ 	ext{mol}^{-1}$)

Accepted Answer

$100.0 	imes 6.022 	imes 10^{23} = 6.022 	imes 10^{25}$ atoms

Question 4

Convert $2.80 	imes 10^5\ \mu	ext{L}$ to mL.

Accepted Answer

$2.80 	imes 10^2\ 	ext{mL}$

Question 5

A car is traveling at $42\ 	ext{miles/hr}$. What is this speed in $	ext{miles/min}$?

Accepted Answer

$0.70\ 	ext{miles/min}$

Question 6

Convert $232\ 	ext{cm}^3$ to liters.

Accepted Answer

$0.232\ 	ext{L}$

Question 7

A solution has a concentration of $15\ 	ext{mol/L}$ of $	ext{C}_6	ext{H}_{12}	ext{O}_7$. How many moles are present in $2.0\ 	ext{L}$ of this solution?

Accepted Answer

$30\ 	ext{mol}$

Question 8

The distance from McAllister Hall to Memorial Library is $0.50\ 	ext{km}$. If the average walking speed is $3.0\ 	ext{miles/hr}$, how many minutes will it take to walk from the library to the chemistry building? (Use $1\ 	ext{mi} = 1.609\ 	ext{km}$)

Accepted Answer

$6.4\ 	ext{minutes}$

Question 9

Which of the following correctly converts $20\ 	ext{m/s}$ to $	ext{km/hr}$?

Accepted Answer

$20\ 	ext{m/s} 	imes \frac{1\ 	ext{km}}{1000\ 	ext{m}} 	imes \frac{3600\ 	ext{s}}{1\ 	ext{hr}} = 72\ 	ext{km/hr}$

Question 10

Which of the following is the correct conversion for $1\ 	ext{in} = 2.54\ 	ext{cm}$?

Accepted Answer

$1\ 	ext{in} = 2.54\ 	ext{cm}$

Question 11

A chemist needs to convert $102\ 	ext{mmol}$ to mol. What is the correct answer?

Accepted Answer

$0.102\ 	ext{mol}$

Question 12

Which of the following best describes the process of dimensional analysis in chemistry?

Accepted Answer

A method of converting units by multiplying by conversion factors so that units cancel appropriately.

Question 13

If a student incorrectly uses $1\ 	ext{mi} = 2.54\ 	ext{km}$ instead of $1\ 	ext{mi} = 1.609\ 	ext{km}$, what will be the effect on their answer when converting miles to kilometers?

Accepted Answer

Their answer will be too large.

Question 14

A laboratory procedure requires $0.500\ 	ext{L}$ of a solution. If you only have a $250\ 	ext{mL}$ graduated cylinder, how many full cylinders do you need to measure out the required volume?

Accepted Answer

2

Question 15

Which of the following is the correct way to express $0.000232\ 	ext{L}$ in scientific notation?

Accepted Answer

$2.32 	imes 10^{-4}\ 	ext{L}$

Question 16

A student is asked to convert $15\ 	ext{km}$ to miles. Which conversion factor should they use?

Accepted Answer

$1\ 	ext{mi} = 1.609\ 	ext{km}$

Unit Conversions and Dimensional Analysis in General Chemistry

Study Guide - Practice Questions

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