Q: How many atoms are in $$0.68$$ moles of zinc? (Use $$1\ \text{mol} = 6.02 \times 10$$^{23}$$ atoms)

$$4.09 \times 10$$^{23}$$ atoms

Question 1

Which of the following best describes an element?

Accepted Answer

A substance that contains only one type of atom and cannot be broken down into simpler substances by chemical means.

Question 2

A sample of lead (Pb) has a mass of $$22.7\ \mathrm{g}$$ and a volume of $$2.0\ \mathrm{cm}^3. $$What is the density of the sample?

Accepted Answer

$$11.35\ \mathrm{g/cm}^3$$

Question 3

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

Accepted Answer

Salt water

Question 4

Which property is intensive and does NOT depend on the amount of substance present?

Accepted Answer

Density

Question 5

A $$119.5\ \mathrm{g}$$ solid cylinder has a radius of $$1.8\ \mathrm{cm}$$ and a height of $$1.5\ \mathrm{cm}. $$What is its density? (Use $$V = \pi r^2$ h)$$

Accepted Answer

$$7.85\ \mathrm{g/cm}^3$$

Question 6

Which of the following is a chemical property?

Accepted Answer

Reactivity with water

Question 7

A $$550\ \mathrm{g}$$ sample of chromium(III) oxide ($$\mathrm{Cr_2O_3}) $$has $$376\ \mathrm{g} of Cr. $$How many grams of Cr are in a $$212\ \mathrm{g}$$ sample of $$\mathrm{Cr_2O_3}$$?

Accepted Answer

$$145\ \mathrm{g}$$

Question 8

Which method would best separate a mixture of sand and iron filings?

Accepted Answer

Using a magnet

Question 9

Which of the following changes is exothermic?

Accepted Answer

Water freezing

Question 10

How many atoms are in $$0.68$$ moles of zinc? (Use $$1\ 	ext{mol} = 6.02 	imes 10$$^{23}$$ atoms)

Accepted Answer

$$4.09 	imes 10$$^{23}$$ atoms

Question 11

Which of the following best describes an alloy?

Accepted Answer

A homogeneous mixture of metals

Question 12

A $$153\ \mathrm{g}$$ rectangular solid has edge lengths $$8.2\ \mathrm{cm}$$, $$5.1\ \mathrm{cm}$$, and $$4.7\ \mathrm{cm}. $$Will this object sink in water? (Density of water $$= 1.00\ \mathrm{g/cm}^3)$$

Accepted Answer

Yes, because its density is greater than water

Question 13

Which of the following is a diatomic element in its natural state?

Accepted Answer

O$$_2$$

Question 14

Which process is used to separate a homogeneous mixture based on differences in boiling points?

Accepted Answer

Distillation

Question 15

A sample of butane ($$\mathrm{C_4H_{10}}) $$contains $$288\ \mathrm{g}$$ carbon and $$60\ \mathrm{g}$$ hydrogen. What is the total mass of the sample?

Accepted Answer

$$348\ \mathrm{g}$$

Question 16

Which of the following is a physical change?

Accepted Answer

Ice melting

Question 17

Which of the following statements about compounds is correct?

Accepted Answer

Compounds have properties different from their constituent elements.

Question 18

Which of the following is an example of an extensive property?

Accepted Answer

Mass

Question 19

Which of the following best describes a heterogeneous mixture?

Accepted Answer

A mixture with different composition and properties in the same sample

Question 20

Which law states that energy cannot be created or destroyed, only transformed?

Accepted Answer

Law of Conservation of Energy

Fundamental Concepts in General Chemistry (Questions test 3)

Study Guide - Practice Questions

Study Guide - Flashcards