Q: A 1.00 g coin is made of pure silver (Ag). How many silver atoms are in the coin? (Molar mass of Ag = 107.9 g/mol, Avogadro’s number = $$6.02 \times 10$$^{23}$$)

$$5.58 \times 10$$^{21}$$ atoms

Q: Which of the following is the correct conversion factor to convert kilometers to miles? (1 mile = 1.61 km)

$$\frac{1 \text{ mi}}{1.61 \text{ km}}$$

Q: Which of the following is the correct calculation for the atomic weight of an element with two isotopes: 51.84% abundance at 106.905 amu and 48.16% abundance at 108.904 amu?

$$106.905 \times 0.5184 + 108.904 \times 0.4816$$

Question 1

Which of the following best explains why water (H$$_2O) is a $$liquid at room temperature while a molecule with a similar mass, such as methane (CH$$_4$$), is a gas?

Accepted Answer

Water molecules have strong hydrogen bonding due to their bent structure.

Question 2

Which statement about the scientific approach to knowledge is correct?

Accepted Answer

It is based on empirical evidence from observation and experiment.

Question 3

A sample contains only one type of particle and has an invariant composition. This sample is best classified as:

Accepted Answer

A pure substance

Question 4

Which law states that the total mass of substances does not change during a chemical reaction?

Accepted Answer

Law of conservation of mass

Question 5

A room measures 12.5 ft $$	imes 15.5 ft$$ $$	imes 8.0 ft. If $$the density of air is 1.19 g/L and 1 ft = 3.05 dm, what is the mass of air in the room in kilograms?

Accepted Answer

$$\approx 52 kg$$

Question 6

Which experiment led to the discovery of the electron’s charge?

Accepted Answer

Millikan’s oil drop experiment

Question 7

Which of the following is true about isotopes?

Accepted Answer

They have the same number of protons but different numbers of neutrons.

Question 8

Calculate the number of moles of O atoms in 0.35 moles of C$$_6H$_{12}O$_6.$$

Accepted Answer

$$2.1$$ moles

Question 9

Which of the following best describes a cation?

Accepted Answer

An atom that has lost electrons

Question 10

A 1.00 g coin is made of pure silver (Ag). How many silver atoms are in the coin? (Molar mass of Ag = 107.9 g/mol, Avogadro’s number = $$6.02 	imes 10$$^{23}$$)

Accepted Answer

$$5.58 	imes 10$$^{21}$$ atoms

Question 11

Which of the following statements about Dalton’s atomic theory is correct?

Accepted Answer

Atoms combine in simple, whole-number ratios to form compounds.

Question 12

Which of the following is a heterogeneous mixture?

Accepted Answer

Sand and iron filings

Question 13

Which scientist is credited with the discovery of the nucleus?

Accepted Answer

Ernest Rutherford

Question 14

If two elements form more than one compound, the ratios of the masses of the second element that combine with a fixed mass of the first element will be ratios of small whole numbers. This is known as:

Accepted Answer

Law of multiple proportions

Question 15

Which of the following is the correct conversion factor to convert kilometers to miles? (1 mile = 1.61 km)

Accepted Answer

$$\frac{1 	ext{ mi}}{1.61 	ext{ km}}$$

Question 16

Which subatomic particle has a mass of approximately $$1.00727$$ amu and a charge of $$+1$$?

Accepted Answer

Proton

Question 17

A sample contains $$9.03 	imes 10$$^{23}$$ molecules of CO_2$. How many moles of O atoms are present?

Accepted Answer

$$3.00$$ moles of O atoms

Question 18

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

Accepted Answer

A compound has a fixed, definite proportion of elements; a mixture does not.

Question 19

Which of the following is the correct calculation for the atomic weight of an element with two isotopes: 51.84% abundance at 106.905 amu and 48.16% abundance at 108.904 amu?

Accepted Answer

$$106.905 	imes 0.5184 + 108.904 	imes 0.4816$$

Chapter 1: Atoms and the Particulate Nature of Matter – General Chemistry Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard