Q: Which of the following best describes a mole in chemistry?

A unit that represents $$6.022 \times 10$$^{23}$$ objects, known as Avogadro's number.

Q: How many atoms are present in 2.00 mol of helium?

$$1.204 \times 10$$^{24}$$ atoms

Question 1

Which of the following best describes a mole in chemistry?

Accepted Answer

A unit that represents $$6.022 	imes 10$$^{23}$$ objects, known as Avogadro's number.

Question 2

How many atoms are present in 2.00 mol of helium?

Accepted Answer

$$1.204 	imes 10$$^{24}$$ atoms

Question 3

A pure gold ring contains $$1.20 	imes 10$$^{22}$$ gold atoms. How many moles of gold does it contain?

Accepted Answer

Question 4

What is the molecular weight (molar mass) of glucose ($$C_6H_{12}O_6$)?

Accepted Answer

$$180.16\ \mathrm{g/mol}$$

Question 5

How many moles of glucose are present in 90.0 g of glucose ($$C_6H_{12}O_6$)?

Accepted Answer

$$0.500$$ mol

Question 6

Which of the following is NOT a characteristic of organic compounds?

Accepted Answer

They contain ionic bonds between carbon and hydrogen.

Question 7

How many valence electrons does a carbon atom have?

Accepted Answer

4

Question 8

Which of the following is the correct Lewis structure for methane ($$CH_4$$)?

Accepted Answer

A central carbon atom with four single bonds to four hydrogen atoms.

Question 9

Which of the following is the correct order for drawing a Lewis dot structure?

Accepted Answer

Count valence electrons, determine central atom, connect atoms with single bonds, add remaining electrons to outer atoms, check octet, form multiple bonds if needed.

Question 10

Which of the following is the condensed structure for butane?

Accepted Answer

$$CH_3CH_2CH_2CH_3$$

Question 11

What is the molecular formula for hexane?

Accepted Answer

$$C_6H_{14}$$

Question 12

Which of the following best describes an alkane?

Accepted Answer

A hydrocarbon with only single bonds between carbon atoms.

Question 13

What is the name of the cycloalkane with the molecular formula $$C_5H_{10}$$?

Accepted Answer

Cyclopentane

Question 14

Which of the following statements about alkanes is TRUE?

Accepted Answer

Alkanes are nonpolar because the electronegativities of carbon and hydrogen are similar.

Question 15

Which of the following is the correct skeletal structure for pentane?

Accepted Answer

A zigzag line with five vertices.

Question 16

If you have $$3.01 	imes 10$$^{23}$$ molecules of water, how many moles of water do you have?

Accepted Answer

$$0.500$$ mol

Question 17

Which of the following is the correct molecular formula for cyclohexane?

Accepted Answer

$$C_6H_{12}$$

Question 18

Which of the following is a correct statement about the difference between a condensed structure and a skeletal structure?

Accepted Answer

A condensed structure shows all atoms, while a skeletal structure shows only the bonds between carbon atoms as lines.

Question 19

Which of the following is the correct name for the alkane with the formula $$C_7H_{16}$$?

Accepted Answer

Heptane

Introduction to Organic Compounds: Structure, Alkanes, and Molecular Representations

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