Question 1

Which of the following is the correct conversion factor for converting micrometers ($$\mu m) to $$meters ($$m$$)?

Accepted Answer

$$1\ \mu m = 10$$^{-6}$$\ m$$

Question 2

A laboratory sample has a mass of $$0.005$$ kilograms. How many milligrams is this? ($$1\ kg = 10^6$\ mg)$$

Accepted Answer

$$5,000\ mg$$

Question 3

When performing a unit conversion, why is it important to arrange the conversion factors so that units are diagonal (cancel)?

Accepted Answer

To cancel out unwanted units and leave only the desired unit

Question 4

Convert $$3.2\$$times10^4$$ nanometers (nm$) to meters (m$). (1$$\ nm = $$10^{-9}$$\ m$$)

Accepted Answer

$$3.2\$$times10^{-5}$$\ m$$

Question 5

A medical test result is reported as $$2.5\ \, \mu L ($$microliters). How many liters is this? ($$1\ \, \mu L = 10$$^{-6}$$\ L)$$

Accepted Answer

$$2.5\$$times10^{-6}$$\ L$$

Question 6

Which of the following steps is NOT part of the standard process for unit conversions as described in the study materials?

Accepted Answer

Multiply all numbers regardless of units

Question 7

If you are converting $$7.5$$ milligrams ($$mg) to $$grams ($$g$$), which conversion factor should you use?

Accepted Answer

$$1\ mg = 10$$^{-3}$$\ g$$

Question 8

A scientist needs to convert $$0.25$$ kilometers ($$km) to $$centimeters ($$cm). $$What is the correct answer? ($$1\ km = 10^3$\ m$$, $$1\ m = 10^2$\ cm)$$

Accepted Answer

$$25,000\ cm$$

Question 9

Why should the number of significant figures in your final answer match the number in the given value during unit conversions?

Accepted Answer

To reflect the precision of the original measurement

Question 10

A prescription requires $$0.75$$ liters of a solution. How many microliters ($$\mu L) is $$this? ($$1\ L = 10^6$\ \mu L)$$

Accepted Answer

$$7.5\$$times10^5$$\ \mu L$$

Question 11

Which prefix corresponds to a factor of $$10^{-12}$$?

Accepted Answer

pico

Question 12

A DNA sample is measured as $$4.2\$$times10^3$$ picograms (pg$). How many grams is this? (1$$\ pg = $$10^{-12}$$\ g$$)

Accepted Answer

$$4.2\$$times10^{-9}$$\ g$$

Question 13

If you are given $$5.0$$ milliliters ($$mL) of a $$solution and need to convert it to liters ($$L$$), what is the correct answer? ($$1\ mL = 10$$^{-3}$$\ L)$$

Accepted Answer

$$5.0\$$times10^{-3}$$\ L$$

Question 14

A student needs to convert $$2.0\$$times10^2$$ microseconds ($$\mu s$$) to seconds (s$). What is the correct answer? (1$$\ \mu s = $$10^{-6}$$\ s$$)

Accepted Answer

$$2.0\$$times10^{-4}$$\ s$$

Question 15

Which of the following best describes the purpose of multiplying straight across the tops and dividing straight across the bottoms in a unit conversion?

Accepted Answer

To ensure the units cancel and the calculation is correct

Question 16

A hospital needs $$1.2\$$times10^5$$ nanograms (ng$) of a drug. How many milligrams (mg$) is this? (1$$\ ng = $$10^{-9}$$\ g$$, 1$$\ mg = $$10^{-3}$$\ g$$)

Accepted Answer

$$1.2\$$times10^{-4}$$\ mg$$

Question 17

Which of the following is the correct order of steps for performing a unit conversion, according to the study materials?

Accepted Answer

Find the given and unknown, find the conversion factor, arrange conversion factors, cancel units, calculate, write answer with correct sig figs

Question 18

A sample contains $$3.0$$ millimoles ($$mmol) of a $$substance. How many moles ($$mol) is $$this? ($$1\ mmol = 10$$^{-3}$$\ mol)$$

Accepted Answer

$$3.0\$$times10^{-3}$$\ mol$$

Question 19

If you are converting $$4.5\$$times10^2$$ micrometers ($$\mu m$$) to nanometers (nm$), what is the correct answer? (1$$\ \mu m = $$10^{-6}$$\ m$$, 1$$\ nm = $$10^{-9}$$\ m$$)

Accepted Answer

$$4.5\$$times10^5$$\ nm$$

Question 20

A chemical reaction produces $$6.0\$$times10^{-2}$$ liters (L$) of gas. How many microliters ($$\mu L$$) is this? (1$$\ L = $$10^6$$\ \mu L$$)

Accepted Answer

$$6.0\$$times10^5$$\ \mu L$$

Unit Conversions and SI Prefixes in Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard