Q: A nurse needs to administer a medication at a dose of 75 mg per kg of body weight. If a child weighs 42 lbs, how many milligrams should be given? (1 kg = 2.2 lbs)

$$75 \times \frac{42}{2.2} = 1432 mg$$

Q: A tablet weighs 0.670 g and contains 325 mg of aspirin. What is the percent aspirin in the tablet?

$$\frac{325}{670} \times 100 = 48.5\%$$

Q: Which of the following is the correct conversion from Celsius to Fahrenheit?

$$^\circ F = (^\circ C \times 1.8) + 32$$

Question 1

Which of the following is an example of a homogeneous mixture?

Accepted Answer

Air in a classroom

Question 2

Which statement best describes a compound?

Accepted Answer

A pure substance made of two or more elements chemically joined together

Question 3

A nurse needs to administer a medication at a dose of 75 mg per kg of body weight. If a child weighs 42 lbs, how many milligrams should be given? (1 kg = 2.2 lbs)

Accepted Answer

$$75 	imes \frac{42}{2.2} = 1432 mg$$

Question 4

Which of the following changes is a chemical change?

Accepted Answer

Iron rusting in moist air

Question 5

How many significant figures are in the measurement 0.00450 mL?

Accepted Answer

3

Question 6

Which of the following is the correct scientific notation for 856,400,000?

Accepted Answer

$$8.564 	imes 10^8$

Question 7

A metal cylinder is dropped into a graduated cylinder containing water. The water level rises from 25.3 mL to 28.9 mL. If the mass of the cylinder is 15.7 g, what is its density?

Accepted Answer

$$\frac{15.7}{3.6} = 4.36 g/mL$$

Question 8

Which of the following elements is a metalloid?

Accepted Answer

Boron (B)

Question 9

Convert a temperature of 306.8 K to Celsius and determine if the patient is suffering from hyperthermia or hypothermia.

Accepted Answer

$$306.8 - 273 = 33.8^\circC$$; hypothermia

Question 10

Which of the following best describes the difference between accuracy and precision?

Accepted Answer

Accuracy is how close measurements are to the true value; precision is how close measurements are to each other.

Question 11

A tablet weighs 0.670 g and contains 325 mg of aspirin. What is the percent aspirin in the tablet?

Accepted Answer

$$\frac{325}{670} 	imes 100 = 48.5\%$$

Question 12

Which of the following is NOT a property of gases?

Accepted Answer

Gases have a definite shape

Question 13

What is the specific gravity of a liquid sample with a density of 1.25 g/mL? (Density of water = 1.00 g/mL)

Accepted Answer

$$\frac{1.25}{1.00} = 1.25$$

Question 14

Which of the following is the correct balanced chemical equation for the reaction of hydrogen and oxygen to form water?

Accepted Answer

$$2H_2 + O_2$ \rightarrow 2H_2O$$

Question 15

A 47.0 mL sample of ethyl alcohol has a density of 0.789 g/mL. What is its mass?

Accepted Answer

$$47.0 	imes 0.789 = 37.1 g$$

Question 16

Which of the following is the correct conversion from Celsius to Fahrenheit?

Accepted Answer

$$^\circ F = (^\circ C 	imes 1.8) + 32$$

Question 17

Which of the following is a correct statement about the law of conservation of mass?

Accepted Answer

The total mass of reactants equals the total mass of products in a chemical reaction.

Question 18

A child should receive 17% of the adult dose of sodium thiopental. If the adult dose is 280 mg, what dose should the child receive?

Accepted Answer

$$280 	imes 0.17 = 47.6 mg$$

Chapter 1: Chemistry Basics—Matter and Measurement (GOB Chemistry Study Notes)

Guida di studio - Domande di pratica

Study guide - Flashcard