Writing Chemical Equations from Word Equations

change

equation

reactants

left

products

right

arrow

yields

add

solid

liquid

gas

aqueous

dissolve in H2O

Symbol

Meaning

(s)

(l)
(g)

(aq)

solid
liquid

gas

aqueous solution
(dissolved in water)

Symbol

Meaning

∆

2 atm

0 °C

MnO2

Reactants are heated. (Or: )
heat

pressure at which reaction is carried out

temperature at which reaction is carried out

formula of a catalyst used

to alter the rate of the reaction

small

atom

large

In front

molecules

two solid
aluminum oxide
molecules

Four solid
aluminum
atoms

three gaseous
oxygen
molecules

Four solid aluminum atoms and three gaseous oxygen molecules react to form
two solid aluminum oxide molecules.

one solid
copper atom

One solid
zinc atom

one aqueous
copper (II) nitrate
molecules

A reaction of one solid zinc atom and one aqueous copper (II) nitrate molecule
yields one solid copper atom and one aqueous zinc nitrate molecule.

one aqueous
zinc nitrate
molecule

Dropdown

How many Hydrogen atoms are in 4 H₂O? ​

Select answer

How many oxygen atoms? ​

Select answer

Multiple Choice

Which of the following is an example that includes evidence of a chemical reaction?

• A sample of zinc is placed in water and it settles to the bottom

• A solid block of ice is heated and it completely melts into a liquid. 

• Sugar that is burned gives off an odor and turns brown and then black.

• A tomato is placed into a blender and chopped up into smaller pieces.

In the previous reaction oxygen is written as
O2 because it is a diatomic element.
There are seven elements that always form diatomic (2
atoms) molecules when they are in their pure state.

H2 N2 O2 F2 Cl2 Br2 I2
These molecules are simply named as the element that they represent.

hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine.

Multiple Choice

Translate the word equation below:

Nitrogen reacts with Hydrogen to form Ammonia (NH₃).

• $$N\ \ \rightarrow\ H\ +\ NH_3$$

• $$N_2\ +\ H_2\ \rightarrow\ NH_3$$

• $$N\ +\ H\ \rightarrow\ NH_3$$

• $$N_2\ \rightarrow\ H_2\ +\ NH_3$$

Drag and Drop

3(NH₄)₂CrO₄

Number of N: ​ ​

Placeholder

Number of H: ​

Placeholder

Number of Cr: ​

Placeholder

Number of O: ​

Placeholder

Drag these tiles and drop them in the correct blank above

6

24

3

12

4

8

1

2

9

Multiple Choice

Translate the word equation below.

Hydrogen and Carbon Dioxide react to form Carbonic Acid (H₂CO₃).

• $$H\ +\ CO_2\ \rightarrow\ H_2CO_3$$

• $$H\ \rightarrow\ CO_2\ +\ H_2CO_{3_{ }}$$

• $$H_2\ +\ CO_2\ \rightarrow\ H_2CO_3$$

• $$H_2\ \rightarrow\ CO_2\ +\ H_2CO_3$$

Multiple Choice

Translate the word equation below.

Carbon Dioxide and Hydrogen react to form Methane (CH₄) and Water

• $$CO_{2_{\ }}+\ H_2O\ \rightarrow\ CH_4\ +H_2\$$

• $$CO_2\ \rightarrow\ H_2\ +\ CH_4\ +\ H_2O$$

• $$CO_2\ \ +\ H_2\ +\ CH_4\ \ \rightarrow\ H_2O$$

• $$CO_2\ \ +\ H_2\ \rightarrow\ CH_4\ +\ H_2O$$

Multiple Choice

In writing an equation that produces hydrogen gas, the correct representation of hydrogen gas is

• H

• 2H

• H₂

• OH

Multiple Choice

According to the law of conservation of mass, the total mass of the reacting substances is

• always more than the total mass of the products

• always less than the total mass of the products

• sometimes more and sometimes less than the total mass of the products

• always equal to the total mass of the products

Drag and Drop

How many elements are in 2 C₆H₁₂O₇?

Placeholder

How many C: ​

Placeholder

How many H: ​

Placeholder

How many O: ​

Placeholder

How many TOTAL atoms: ​

Placeholder

Drag these tiles and drop them in the correct blank above

3

12

24

14

50

7

6

25

52

60

Multiple Choice

In an equation, the symbol for a substance in water solution is followed by

• (l)

• (g)

• (aq)

• (s)

Multiple Choice

Which of the following is a formula equation for the formation of carbon dioxide from carbon and oxygen?

• Carbon plus oxygen yields carbon dioxide

• C + O₂ ---> CO₂

• CO₂ ---> C + O₂

• 2C + O --->CO₂

Multiple Choice

For the formula equation 2Mg + O₂ ---> 2MgO, the word equation would begin

• Manganese plus oxygen . . . .

• Molybdenum plus oxygen . . . .

• Magnesium plus oxygen . . . .

• Heat plus oxygen