Oxidation Numbers and Their Rules

This video tutorial by Dr. English covers the basics of redox reactions, focusing on oxidation numbers. It explains how to assign oxidation numbers, the rules governing them, common oxidation numbers, and exceptions. The tutorial provides step-by-step guidance on assigning oxidation numbers in compounds, with examples and practice problems to reinforce learning.

What is the range of oxidation numbers typically assigned to elements?

• From -4 to +8, excluding zero

• From -2 to +6, including zero

• From -5 to +5, excluding zero

• From -3 to +7, including zero

What is the oxidation number of a free element?

• It varies depending on the element

• Always zero

• Always positive

• Always negative

Which group of elements always has an oxidation number of +1?

• Transition metals

• Noble gases

• Group 1 elements

• Group 2 elements

In which type of compound does hydrogen have an oxidation number of -1?

• In acids

• In metal hydrides

• In compounds with nonmetals

• In peroxides

What is the oxidation number of oxygen in most compounds?

• +2

• 0

• -2

• -1

What is the first step in assigning oxidation numbers to atoms in a compound?

• Assign oxidation numbers to the least electronegative element

• Assign oxidation numbers based on known rules

• Assign oxidation numbers randomly

• Assign oxidation numbers to the most electronegative element

In the compound H2SO4, what is the oxidation number of sulfur?

• +6

• +4

• -2

• 0

In the compound K2Cr2O7, what is the oxidation number of chromium?

• +6

• +2

• +3

• +4

In the compound NiBr3, what is the oxidation number of nickel?

• +1

• +2

• +3

• +4

In the compound Al(OH)3, what is the oxidation number of aluminum?

• +1

• +2

• +4

• +3