Question 1

Which of the following elements in its natural state has an oxidation number of zero?

Accepted Answer

Helium, He

Question 2

What is the oxidation number of oxygen in hydrogen peroxide ($\mathrm{H_2O_2}$)?

Accepted Answer

$-1$

Question 3

Which element would have the most positive oxidation number based on its ionic form?

Accepted Answer

Scandium, Sc

Question 4

Which of the following elements would have the lowest oxidation number?

Accepted Answer

Strontium, Sr

Question 5

In which compound does oxygen have the lowest oxidation state?

Accepted Answer

$\mathrm{Cs_2O_2}$

Question 6

What is the oxidation number of fluorine in all its compounds?

Accepted Answer

$-1$

Question 7

Which rule is used to determine the oxidation number of hydrogen when it is bonded to a metal?

Accepted Answer

Hydrogen is assigned $-1$

Question 8

What is the oxidation number of chlorine in $\mathrm{NaClO_3}$?

Accepted Answer

$+5$

Question 9

If the sum of oxidation numbers in a neutral compound must equal zero, what is the sum in $\mathrm{K_2SO_4}$?

Accepted Answer

$0$

Question 10

Which element is most likely to have an oxidation number of $+2$ in its ionic form?

Accepted Answer

Calcium, Ca

Question 11

What is the oxidation number of sulfur in $\mathrm{H_2SO_4}$?

Accepted Answer

$+6$

Question 12

Which of the following is true about the oxidation number of an element in its natural state?

Accepted Answer

It is always $0$

Question 13

What is the oxidation number of nitrogen in $\mathrm{NH_3}$?

Accepted Answer

$-3$

Question 14

Which of the following compounds contains an element with an oxidation number of $+1$?

Accepted Answer

$\mathrm{NaCl}$

Question 15

In the compound $\mathrm{H_2O}$, what is the oxidation number of hydrogen?

Accepted Answer

$+1$

Question 16

Which of the following elements is most likely to have an oxidation number of $-2$ in a compound?

Accepted Answer

Oxygen, O

Question 17

What is the oxidation number of potassium in $\mathrm{K_2O}$?

Accepted Answer

$+1$

Question 18

Which of the following is a correct step when determining the oxidation number of a non-listed element in a compound?

Accepted Answer

Treat the non-listed element as $x$

Question 19

In $\mathrm{CO_2}$, what is the oxidation number of carbon?

Accepted Answer

$+4$

Question 20

Which of the following statements about oxidation numbers is correct?

Accepted Answer

Oxidation numbers are used to keep track of electron transfer in reactions

Oxidation Numbers and Their Rules in GOB Chemistry

Study Guide - Practice Questions