Q: A chemist needs to convert $$2.50\ \text{L} to$$ $$\text{cm}^3. $$Which conversion factor should be used, and what is the correct answer?

Use $$1\ \text{L} = 1000\ \text{cm}^3$$; $$2.50\ \text{L} = 2500\ \text{cm}^3$$

Q: A sample of water absorbs $$1500\ \text{J} of $$heat, causing its temperature to rise by $$3.6\ ^\circ\text{C}. If $$the mass of the water is $$100\ \text{g}$$, what is the specific heat of water based on this experiment?

$$4.2\ \text{J/g}^\circ\text{C}$$

Q: A student wants to convert $$25.0\ ^\circ\text{C} to $$Fahrenheit. Which equation should be used, and what is the correct answer?

Use $$F = \frac{9}{5}C + 32$$; $$25.0\ ^\circ\text{C} = 77.0\ ^\circ\text{F}$$

Q: A student is given a solution map to convert $$5.0\ \text{km} to$$ $$\text{cm}. $$Which sequence of conversion factors should be used?

$$5.0\ \text{km} \times \frac{1000\ \text{m}}{1\ \text{km}} \times \frac{100\ \text{cm}}{1\ \text{m}}$$

Question 1

Which of the following best describes the difference between a scientific law and a scientific theory?

Accepted Answer

A scientific law is a summary of observed phenomena, while a theory provides an explanation for those phenomena.

Question 2

A student measures the mass of a sample as 12.345 g and its volume as 4.2 mL. What is the density of the sample, reported with the correct number of significant figures?

Accepted Answer

$$3.0\ 	ext{g/mL}$$

Question 3

Which of the following is an example of a physical property?

Accepted Answer

The boiling point of water

Question 4

A chemist needs to convert $$2.50\ 	ext{L} to$$ $$	ext{cm}^3. $$Which conversion factor should be used, and what is the correct answer?

Accepted Answer

Use $$1\ 	ext{L} = 1000\ 	ext{cm}^3$$; $$2.50\ 	ext{L} = 2500\ 	ext{cm}^3$$

Question 5

Which of the following statements about the conservation of mass is correct?

Accepted Answer

Mass is conserved; the total mass before and after a chemical reaction is the same.

Question 6

A sample of water absorbs $$1500\ 	ext{J} of $$heat, causing its temperature to rise by $$3.6\ ^\circ	ext{C}. If $$the mass of the water is $$100\ 	ext{g}$$, what is the specific heat of water based on this experiment?

Accepted Answer

$$4.2\ 	ext{J/g}^\circ	ext{C}$$

Question 7

Which of the following is NOT a SI unit?

Accepted Answer

Calorie

Question 8

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Question 9

A student wants to convert $$25.0\ ^\circ	ext{C} to $$Fahrenheit. Which equation should be used, and what is the correct answer?

Accepted Answer

Use $$F = \frac{9}{5}C + 32$$; $$25.0\ ^\circ	ext{C} = 77.0\ ^\circ	ext{F}$$

Question 10

Which of the following statements about the atomic theory of matter is correct?

Accepted Answer

Atoms of a given element are identical in mass and properties.

Question 11

A compound contains only carbon and oxygen. Which classification best describes this substance?

Accepted Answer

Compound

Question 12

Which of the following is a correct statement about ions?

Accepted Answer

An ion forms when an atom gains or loses electrons.

Question 13

A student is given a solution map to convert $$5.0\ 	ext{km} to$$ $$	ext{cm}. $$Which sequence of conversion factors should be used?

Accepted Answer

$$5.0\ 	ext{km} 	imes \frac{1000\ 	ext{m}}{1\ 	ext{km}} 	imes \frac{100\ 	ext{cm}}{1\ 	ext{m}}$$

Question 14

Which of the following is a chemical property?

Accepted Answer

Ability of hydrogen to react with oxygen

Question 15

A sample contains $$^{24}	ext{Mg}$$, $$^{25}	ext{Mg}$$, and $$^{26}	ext{Mg}$$ isotopes with abundances of $$79\%$$, $$10\%$$, and $$11\%$$ respectively. What is the average atomic mass of magnesium?

Accepted Answer

$$24.32$$

Question 16

Which of the following best describes the kinetic energy of molecules in a gas compared to a solid?

Accepted Answer

Molecules in a gas have more kinetic energy than those in a solid.

Question 17

A student adds $$2.0\ 	ext{g} of $$salt to $$100\ 	ext{g} of $$water and stirs until dissolved. What type of matter is the resulting mixture?

Accepted Answer

Homogeneous mixture

Question 18

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

Accepted Answer

$$K = C + 273.15$$

Question 19

A student multiplies $$2.50 by$$ $$3.00$$ and divides by $$1.20. $$How many significant figures should the final answer have?

Accepted Answer

2

Exam I Study Guide: Introduction to Chemistry (Chapters 1–4)

Guida di studio - Domande di pratica

Study guide - Flashcard