G10 Unit 26 Chemical Equations in Words and Symbols

Question 1

Chemical equations show what happens in a chemical reaction

Question 2

The reactants are placed on the left-hand side and the products are given on the right-hand side, with an arrow in between to show the direction of the reaction:

Answer 2

reactants→products

Question 3

In cases with multiple reactants or products, a plus sign (“+”) is used

Answer 3

reactant 1+reactant 2→product 1+product 2

Question 4

For example, a reaction between solid sodium carbonate and hydrochloric acid solution forms sodium chloride, water, and carbon dioxide. This reaction is written as: sodium carbonate+hydrochloric acid→sodium chloride+water+carbon dioxide

Question 5

Chemical equations, similar to mathematical equations, can be expressed both in words and in symbols.

Question 6

Writing chemical equations using chemical symbols and formulas are more practical as it allows you to see all the elements and their ratio in a compound in a reactant or product. Na2CO3 (s)+2HCl (aq)→2NaCl (aq)+2H2O (l)+CO2 (g)

Question 7

One significant chemical change that naturally occurs inside your body is the breakdown and digestion of table sugar or sucrose.
With the help of the enzyme amylase, table sugar can be broken into smaller units of glucose and fructose, according to the equation expressed in words: sucroseamylase−−−−→glucose+fructose

Question 8

When you represent the substances with their chemical symbols, the chemical equation becomes: C12H22O11 (s)amylase−−−−→C6H12O6 (s)+C6H12O6 (s)
Take note that fructose and glucose have the same chemical formula, but their structures in three-dimensional space are different.
Also, take note that to represent enzymes in equations, they are added above the arrow.

Question 9

In other cases, energy is needed to initiate reactions.

Question 10

where a single reactant is broken down into smaller products

Answer 10

endothermic decomposition reactions

Question 11

The energy comes in the form of heat, electricity or light.

Question 12

Heat and electricity are represented by the uppercase Greek letter

Answer 12

delta, Δ

Question 13

light is represented by the combination of symbol

Answer 13

hv

Question 14

Writing Chemical Equations

As an example, consider the decomposition of limestone.
Limestone, which is made up of calcium carbonate, decomposes to calcium oxide and carbon dioxide exposed under intense heat.
The equation can be expressed in words as: calcium carbonateΔ−→calcium oxide+carbon dioxide

In symbols: CaCO3 (s)Δ−→CaO (s)+CO2 (g)