AP Chemistry Chapter Three Review Questions

Determine the mass of oxygen in a 7. g samples of Al₂(SO₄)₃ A) 4.0 g O B) 0.34 g P C) 8.0 g O D) 1.4 x 10³ g O

A) 4.0 g O

Find the number of ibuprofen molecules in a tablet containing 200.0 mg of ibuprofen (C₁₃H₁₈O₂) A) 5.839 x 10²⁰ C₁₃H₁₈O₂ molecules B) 5.839 x 10²³ molecules C) 2.484 x 10²³ moleules D) 1.610 x 10⁻² molecules

A) 5.839 x 10²⁰ C₁₃H₁₈O₂ molecules

What is the correct formula for the compound that forms calcium and sulfur? A) CaS B) Ca₂S C) CaS₂ D) CaS₃

A) CaS

Write the formula for the compound formed between potassium and sulfur. A) K₂S B) KS₂ C) KS

A) K₂S

Which substance is an ionic compound? A) SrI₂ B) N₂O₄ C) He D) CCl₄

A) SrI₂

Name the compound SrI₂. A) Strontium iodide B) Strontium diodide C) Strontium (II) iodide D) Strontium (II) diiodide

A) Strontium iodide

Determine the number of CH₂Cl₂ molecules are there in 25.0 g CH₂Cl₂? A) 0.294 molecules B) 1.77 x 10²³ molecules C) 1.28 x 10²⁷ molecules D) 1.51 x 10²⁵ molecules

B) 1.77 x 10²³ molecules

Combustion of 30.42 g of a compound containing only carbon, hydrogen, and oxygen produces 35.21 g CO₂ and 14.42 g H₂O. What is the empirical formula of the compound? A) C₄H₈O₆ B) C₂H₄O₃ C) C₂H₂O₃ D) C₆HO₁₂

B) C₂H₄O₃

A compound is 52.14% C, 13.13% H, and 34.73% O by mass. What is the empirical formula of the compound? A) C₂H₈O₃ B) C₂H₆O C) C₄HO₃ D) C₃HO₆

B) C₂H₆O

Select the structural formula for water A) H₂O B) H-O-H C) H-O D) H-H

B) H-O-H

What type of bond forms between nitrogen and oxygen? A) ionic B) covalent

B) covalent

Name the compound Pb(C₂H₃O₂)₂. A) lead (II) carbonate B) lead (II) acetate C) lead bicarbonate D) lead diacetate

B) lead (II) acetate

Without doing amy calculations , list the elements in C₆H₆O in order of decreasing mass percent comp.

C > O > H

Determine the mass of potassium in 35.5 g of KBr. A) 108 g B) 0.298 g C) 11.7 g D) 32.9 g

C) 11.7 g

The molecular formula for water is H₂O. Which ratio can be correctly derived from this formula? Explain. A) 2 g H : 1 g H₂O B) 2 mL H : 1 mL H₂O C) 2 mol H : 2 mol H₂O

C) 2 mol H : 2 mol H₂O Chemical formulas give relationships between aoms or moles of atoms per mole of the molecule.

Identify the polatomic ion and its charge in each compound: KNO₂, CaSO₄, Mg(NO₃)₂ A) K⁺, Ca²⁺, and Mg²⁺ B) NO₂²⁺, SO₄⁻, and NO₃²⁻ C) NO₂⁻, SO₄²⁻, and NO₃⁻ D) K⁺, Ca²⁺, Mg²⁺, NO₂⁻, SO₄²⁻, and NO₃⁻ Extra: Name the three compounds.

C) NO₂⁻, SO₄²⁻, and NO₃⁻ Potassium Nitrite, Calcium Sulfate, Magnesium (II) Nitrate

List the elements in the compound CF₂Cl₂ in order of decreasing mass percent composition.

Cl > F > C

What is the empirical formula of a compound w/the molecular formula C₁₀H₈?

C₅H₄

A compound has the empirical formula CH₂O and a formula mass of 120.10 amu. What is the molecular formula of the compound? A) CH₂O B) C₂H₄O₂ C) C₃H₆O₃ D) C₄H₈O₄

D) C₄H₈O₄

What is the forula for manganese (IV) oxide> A) Mn₄O B) MnO₄ C) Mn₂O D) MnO₂

D) MnO₂

Which metal has the same charge in all of its compounds? A) Fe B) Mo C) Pb D) Sr

D) Sr

Name the compound P₂I₄. A) phosphorus iodide B) phosphorus diiodide C) phosphorus (II) iodide D) diphorphorus tetraiodide

D) diphophorus tetraiodide

Name the compound HNO₂(aq) A) hydrogen nitrogen dioxide B) hydrogen nitrite C) nitric acid D) nitrous acid

D) nitrous acid

Name H₂SO₃ (aq).

Sulfurous acid (dihydrogen sulfate)

The compound NCl₃ is nitrogen trichloride, but AlCl₃ is simply aluminum chloride. Why?

The name forms differ becasue NCl₃ is a molecualr compound and AlCl₃ is an ionic compound. Prefixes such as mono-, di-, tri- are used for molecular compounds but not for ionic compounds.