Q: A nurse measures a patient's body temperature as 38.5 $^{\circ}$C. What is this temperature in Kelvin?

$K = ^{\circ}C + 273$;\newline K = 38.5 + 273 = 311.5\ K$

Q: A sample of metal has a mass of 48.0 g and raises the water level in a graduated cylinder from 25.0 mL to 33.0 mL. What is the density of the metal?

$\text{Density} = \frac{48.0\ g}{33.0\ mL - 25.0\ mL} = \frac{48.0\ g}{8.0\ mL} = 6.0\ g/mL$

Q: A doctor prescribes 0.150 mg of medication. If each tablet contains 75 mcg, how many tablets are needed?

$0.150\ mg \times \frac{1000\ mcg}{1\ mg} = 150\ mcg;\newline \frac{150\ mcg}{75\ mcg/tablet} = 2\ tablets$

Q: Convert 2.44 meters to centimeters.

$2.44\ m \times \frac{100\ cm}{1\ m} = 244\ cm$

Q: A patient’s body mass is 164 lb. What is the mass in kilograms? (Use $1\ kg = 2.20\ lb$)

$164\ lb \times \frac{1\ kg}{2.20\ lb} = 74.5\ kg$

Q: A cup of coffee contains 95 mg of caffeine. If the $LD_{50}$ for caffeine is 192 mg/kg, how many cups would a 70 kg person need to consume to reach the $LD_{50}$?

$192\ mg/kg \times 70\ kg = 13,440\ mg;\newline \frac{13,440\ mg}{95\ mg/cup} \approx 141.5\ cups$

Question 1

A nurse measures a patient's body temperature as 38.5 $^{\circ}$C. What is this temperature in Kelvin?

Accepted Answer

$K = ^{\circ}C + 273$;
ewline K = 38.5 + 273 = 311.5\ K$

Question 2

Which of the following is an exact number?

Accepted Answer

The number of eggs in a dozen

Question 3

A sample of metal has a mass of 48.0 g and raises the water level in a graduated cylinder from 25.0 mL to 33.0 mL. What is the density of the metal?

Accepted Answer

$	ext{Density} = \frac{48.0\ g}{33.0\ mL - 25.0\ mL} = \frac{48.0\ g}{8.0\ mL} = 6.0\ g/mL$

Question 4

Which of the following numbers has three significant figures?

Accepted Answer

0.00450

Question 5

A doctor prescribes 0.150 mg of medication. If each tablet contains 75 mcg, how many tablets are needed?

Accepted Answer

$0.150\ mg 	imes \frac{1000\ mcg}{1\ mg} = 150\ mcg;
ewline \frac{150\ mcg}{75\ mcg/tablet} = 2\ tablets$

Question 6

Which of the following is the correct equality for the prefix 'centi-'?

Accepted Answer

$1\ cm = 0.01\ m$

Question 7

A can of food is labeled as 425 g (15 oz). Which of the following statements is true about the numbers 425 and 15?

Accepted Answer

Both 425 and 15 are measured numbers

Question 8

Which of the following objects will float in water (density = 1.00 g/mL)?

Accepted Answer

Cork (density = 0.26 g/mL)

Question 9

Convert 2.44 meters to centimeters.

Accepted Answer

$2.44\ m 	imes \frac{100\ cm}{1\ m} = 244\ cm$

Question 10

A patient’s body mass is 164 lb. What is the mass in kilograms? (Use $1\ kg = 2.20\ lb$)

Accepted Answer

$164\ lb 	imes \frac{1\ kg}{2.20\ lb} = 74.5\ kg$

Question 11

Which of the following is the correct conversion factor for the equality $1\ m = 100\ cm$?

Accepted Answer

$\frac{100\ cm}{1\ m}$

Question 12

A solution contains 0.5 ppm mercury. What does 'ppm' stand for in this context?

Accepted Answer

parts per million

Question 13

A thermometer reads $-15^{\circ}$F. What is this temperature in $^{\circ}$C? (Use $^{\circ}C = (^{\circ}F - 32)/1.8$)

Accepted Answer

$^{\circ}C = (-15 - 32)/1.8 = -26^{\circ}C$

Question 14

Which of the following is NOT a rule for determining significant figures?

Accepted Answer

Zeros at the beginning of a decimal number are significant.

Question 15

A cup of coffee contains 95 mg of caffeine. If the $LD_{50}$ for caffeine is 192 mg/kg, how many cups would a 70 kg person need to consume to reach the $LD_{50}$?

Accepted Answer

$192\ mg/kg 	imes 70\ kg = 13,440\ mg;
ewline \frac{13,440\ mg}{95\ mg/cup} \approx 141.5\ cups$

Chapter 1: Chemistry and Measurements – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards