Properties of the Elements

Question 1

Elemental form of Nitrogen

Answer 1

Gas (N₂)

Question 2

Elemental form of group 15 (i.e. pnictogens) from Phosphorus to Bismuth.

Answer 2

Soilds

Question 3

Elemental form of oxygen

Answer 3

Dioxygen (gas)

Question 4

This class of compounds react with water to generate protons.

Answer 4

Acidic Oxides​ (Non-Metals)

NO₂⁺ H₂O —> HNO₃ + H⁺

Question 5

This class of compounds react with water to generate protons.

Answer 5

Acidic Oxides​ (Non-Metals)

NO₂⁺ H₂O —> HNO₃ + H⁺

Question 6

This class of compounds react with water to generate hydroxide.

Answer 6

Basic oxides

MgO + H₂O —> Mg(OH)₂

Fe₂O₃ + 3H₂O —-> 2 Fe(OH)₃

Question 7

This class of compounds react with water (most do, a few do not) always generate acidic solutions.

Answer 7

Covalent oxides

e.g. BeO

Question 8

This class of compounds always react with water to generate basic solutions

Answer 8

Ionic oxides

e.g. ZnO , MnO_2​

Question 9

A compound that can chemically react as either acid or base.

Answer 9

Amphoterism

• Al₂O₃ + 2NaOH —-> 2NaAlO₂ + H₂O (acts as an acid)*
• Al₂O₃ + 6 HCl —-> 2 AlCl₃ + 6H₂O (acts as a base)*

Question 10

A compound that can chemically react as either acid or base.

Answer 10

Amphoterism

• Al₂O₃ + 2NaOH —-> 2NaAlO₂ + H₂O (acts as an acid)*
• Al₂O₃ + 6 HCl —-> 2 AlCl₃ + 6H₂O (acts as a base)*

Question 11

The prefix and suffix that denotes the lowest oxidation state of the central atom of a given oxo compound

Answer 11

Hypo​-**basename**-ous​/ite

e.g. HOBr—>Hypo​bromous acid (acid form)

BrO^- —-> Hypo**brom**ite(base form)

Question 12

The prefix and suffix that denotes the highest oxidation state of the central atom of a given oxo compound

Answer 12

per​-**basename-**ate/ic

e.g. ClO₄⁻ —>per**chlor**ate (base form)

HClO₄ —–> per**chlor**ic acid (acid form)

Question 13

For polyprotic oxoacids the acidity _______ as each successive proton is removed

Increases or decreases

Answer 13

Decreases

HCO₃⁻ (10.3) vs H₂CO₃(3.6)

Question 14

For an oxoacids of a given central atom the acidity _____ with the central element’s oxidation state.

Increases or decreases

Answer 14

Increases

HOCl (7.5) vs HClO₂ (1.94)

+1 ox. state vs +3 ox. state

(Pauling’s Rules for Oxo Acids)

Question 15

In a homologous series the acidity _______with the electronegativity of the central atom.

Increases or decreases

Answer 15

Increases

HOCl (7.5) vs HOBr (8.7)