$$\frac{32.00}{44.01} \times 100 = 72.73\%$$

$$5.32 \times 3 \times 6.022 \times 10$$^{23}$$

Question 1

Which statement best explains why water (H$$_2O) $$has properties different from its constituent elements hydrogen and oxygen?

Accepted Answer

Water is a compound with unique chemical and physical properties due to the bonding of hydrogen and oxygen atoms.

Question 2

Which of the following is a correct empirical formula for glucose, C$$_6H$_{12}O$_6$$?

Accepted Answer

$$\mathrm{CH}_2\mathrm{O}$$

Question 3

Which of the following best describes an ionic compound?

Accepted Answer

A compound composed of positively and negatively charged ions held together by electrostatic attraction.

Question 4

What is the correct name for the compound FeCl$$_3$$?

Accepted Answer

Iron(III) chloride

Question 5

Which formula represents the smallest electrically neutral unit in an ionic compound?

Accepted Answer

Formula unit

Question 6

A compound contains 62.58% C, 9.63% H, and 27.79% O by mass. What is its empirical formula?

Accepted Answer

$$\mathrm{C}_4\mathrm{H}_8\mathrm{O}_2$$

Question 7

Which of the following is the correct formula for calcium phosphate?

Accepted Answer

$$\mathrm{Ca}_3(\mathrm{PO}_4)_2$$

Question 8

What is the mass percent of oxygen in CO$$_2$$? (Atomic masses: C = 12.01 g/mol, O = 16.00 g/mol)

Accepted Answer

$$\frac{32.00}{44.01} 	imes 100 = 72.73\%$$

Question 9

Which of the following is a correct name for the compound N$$_2O$_5$$?

Accepted Answer

Dinitrogen pentoxide

Question 10

How many moles of hydrogen atoms are present in 50.0 g of methane (CH$$_4$$)? (Atomic masses: C = 12.01 g/mol, H = 1.008 g/mol)

Accepted Answer

4.98 mol

Question 11

Which of the following is the correct formula for magnesium sulfate heptahydrate?

Accepted Answer

$$\mathrm{MgSO}_4 \cdot 7\mathrm{H}_2\mathrm{O}$$

Question 12

Which of the following is a correct name for H$$_2SO$_4(aq$$)?

Accepted Answer

Sulfuric acid

Question 13

What is the molecular formula of a compound with empirical formula CH$$_2O $$and a molar mass of 180 g/mol? (Molar mass of CH$$_2O = 30 g/$$mol)

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6$$

Question 14

Which of the following is the correct name for Na$$_2CO$_3$$ · 10H$$_2O$$?

Accepted Answer

Sodium carbonate decahydrate

Question 15

Which of the following is a correct formula for ammonium nitrate?

Accepted Answer

$$\mathrm{NH}_4\mathrm{NO}_3$$

Question 16

Which of the following is a correct name for HCl(aq)?

Accepted Answer

Hydrochloric acid

Question 17

How many oxygen atoms are present in 5.32 moles of CaCO$$_3$$?

Accepted Answer

$$5.32 	imes 3 	imes 6.022 	imes 10$$^{23}$$

Question 18

Which of the following is the correct name for P$$_4O$_{10}$$?

Accepted Answer

Tetraphosphorus decoxide

Question 19

Which of the following is a correct formula for copper(I) oxide?

Accepted Answer

$$\mathrm{Cu}_2\mathrm{O}$$

Chapter 3: Molecules and Compounds – General Chemistry Study Notes

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