Q: Convert $$2.50\ \mathrm{kg} to $$grams and report your answer with the correct number of significant figures.

$$2.50 \times 10^3$\ \mathrm{g}$$

Question 1

Which of the following best describes a homogeneous mixture?

Accepted Answer

A mixture in which the composition is uniform throughout, such as salt dissolved in water.

Question 2

A student measures the mass of a metal sample four times and records the following values: 3.52 g, 3.56 g, 3.49 g, and 3.51 g. The true mass is 2.50 g. Which statement best describes the accuracy and precision of these measurements?

Accepted Answer

The measurements are precise but not accurate.

Question 3

Which of the following is a chemical property?

Accepted Answer

Iron rusts when exposed to oxygen.

Question 4

Convert $$2.50\ \mathrm{kg} to $$grams and report your answer with the correct number of significant figures.

Accepted Answer

$$2.50 	imes 10^3$\ \mathrm{g}$$

Question 5

A patient is prescribed $$1.25\ \mathrm{g} of $$amoxicillin. If each tablet contains $$250\ \mathrm{mg}$$, how many tablets are needed?

Accepted Answer

5 tablets

Question 6

Which of the following is the correct equivalence statement for converting centimeters to meters?

Accepted Answer

$$1\ \mathrm{m} = 100\ \mathrm{cm}$$

Question 7

A gold bar has dimensions $$15.5\ \mathrm{cm} 	imes 27.3\ \mathrm{cm} 	imes 5.40\ \mathrm{in}. If $$the density of gold is $$19.32\ \mathrm{g/mL}$$ and $$1\ \mathrm{in} = 2.54\ \mathrm{cm}$$, what is the mass of the bar in kilograms? (Report to 3 significant figures.)

Accepted Answer

$$44.2\ \mathrm{kg}$$

Question 8

Which of the following numbers has 3 significant figures?

Accepted Answer

0.00570

Question 9

A child is prescribed $$160\ \mathrm{mg} of $$ibuprofen. If the liquid medication contains $$100\ \mathrm{mg}$$ per $$5\ \mathrm{mL}$$, how many milliliters should be given?

Accepted Answer

$$8.0\ \mathrm{mL}$$

Question 10

Which of the following is the correct formula for converting Celsius to Kelvin?

Accepted Answer

$$K = ^\circ\!C + 273.15$$

Question 11

A sample has a mass of $$122\ \mathrm{g}$$ and a volume of $$121\ \mathrm{mL}. $$What is its density in $$\mathrm{g/mL} (to $$the correct number of significant figures)?

Accepted Answer

$$1.01\ \mathrm{g/mL}$$

Question 12

Which of the following is a derived SI unit?

Accepted Answer

Liter ($$\mathrm{L})$$

Question 13

A hospital has $$125\ \mathrm{dL} of $$blood plasma. How many liters is this?

Accepted Answer

$$12.5\ \mathrm{L}$$

Question 14

Which of the following best describes the difference between an element and a compound?

Accepted Answer

An element is a pure substance made of only one kind of atom, while a compound is made of two or more elements chemically combined.

Question 15

A dose of $$240\ \mathrm{mg} of $$acetaminophen is prescribed for a $$20\ \mathrm{kg}$$ child. If Children’s Tylenol contains $$80\ \mathrm{mg} in$$ $$2.5\ \mathrm{mL}$$, how many milliliters are needed?

Accepted Answer

$$7.5\ \mathrm{mL}$$

Question 16

Which of the following statements about significant figures is correct?

Accepted Answer

When multiplying or dividing, the answer should have the same number of significant figures as the measurement with the fewest significant figures.

Question 17

A patient weighing $$133\ \mathrm{lb} is $$prescribed isotretinoin at a dose of $$0.5\ \mathrm{mg/kg}. $$How many $$20\ \mathrm{mg}$$ tablets are needed? ($$1\ \mathrm{lb} = 0.454\ \mathrm{kg})$$

Accepted Answer

2 tablets

Question 18

Which of the following is the correct scientific notation for the number $$0.0002650$$?

Accepted Answer

$$2.650 	imes 10$$^{-4}$$

Question 19

The LD$$_{50} of $$caffeine is $$192\ \mathrm{mg/kg}. If a $$person weighs $$70.0\ \mathrm{kg}$$, what is the approximate lethal dose in grams?

Accepted Answer

$$13.4\ \mathrm{g}$$

Chapter 1: Matter, Energy, and Measurement – Foundations of General Chemistry

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