Question 1

Which of the following best describes a compound?

Accepted Answer

A pure substance composed of two or more different elements in a fixed, definite proportion.

Question 2

What is the correct empirical formula for hydrogen peroxide, given its molecular formula is $$\mathrm{H_2O_2}$$?

Accepted Answer

$$\mathrm{HO}$$

Question 3

Which of the following elements exists as a diatomic molecule in its natural state?

Accepted Answer

Nitrogen ($$\mathrm{N_2$})$$

Question 4

What type of bond is formed when a metal reacts with a nonmetal?

Accepted Answer

Ionic bond

Question 5

Which of the following is the correct chemical formula for sodium nitrate?

Accepted Answer

$$\mathrm{$$NaNO_3$$}$$

Question 6

A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is its empirical formula?

Accepted Answer

$$\mathrm{CH_2O}$$

Question 7

Which statement about ionic compounds is TRUE?

Accepted Answer

They consist of a three-dimensional array of cations and anions.

Question 8

What is the correct name for the compound $$\mathrm{Fe_2O_3}$$?

Accepted Answer

Iron(III) oxide

Question 9

Which of the following is a polyatomic ion?

Accepted Answer

$$\mathrm{NO_3$^-}$$

Question 10

What is the molar mass of $$\mathrm{CO_2$}$$?

Accepted Answer

$$44.01\ \mathrm{g/mol}$$

Question 11

Which of the following is the correct formula for potassium sulfate?

Accepted Answer

$$\mathrm{K_2SO_4}$$

Question 12

A sample contains $$3.55 	imes 10$$^{24}$$ molecules of water. How many moles of water are present?

Accepted Answer

$$5.90$$ moles

Question 13

Which of the following is the correct name for $$\mathrm{N_2O_5}$$?

Accepted Answer

Dinitrogen pentoxide

Question 14

What is the mass percent of chlorine in $$\mathrm{$$CCl_4$$}$$? (C: 12.01 g/mol, Cl: 35.45 g/mol)

Accepted Answer

$$76.4\%$$

Question 15

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

Accepted Answer

$$\mathrm{(NH_4$)_3PO_4}$$

Question 16

Which of the following compounds contains a transition metal with variable charge?

Accepted Answer

$$\mathrm{CuO}$$

Question 17

What is the correct name for $$\mathrm{Na_2CO_3 \cdot 10H_2O}$$?

Accepted Answer

Sodium carbonate decahydrate

Question 18

Which of the following is the correct molecular formula for phosphorus triiodide?

Accepted Answer

$$\mathrm{PI_3$}$$

Question 19

A compound has an empirical formula of $$\mathrm{CH}$$ and a molar mass of $$78.11\ \mathrm{g/mol}. $$What is its molecular formula?

Accepted Answer

$$\mathrm{C_6H_6}$$

Question 20

Which of the following is the correct formula for the hypochlorite ion?

Accepted Answer

$$\mathrm{ClO^-}$$

Ch.3 Molecules and Compounds: Study Notes

Guida di studio - Domande di pratica