PAGE 2 - INTRO TO BALANCING
On this page will have a look at equations and how to balance them.
So, let's take an example to look at:
sodium + hydrochloric acid —> sodium chloride + hydrogen
This is an example of a word equation.
Now, let's produce a symbol equation.
Na + HCl —> NaCl + H2
Buts is this a balanced equation?
No, it's not:
One thing we need to remember from page 1 was that you must have the same number of atoms on the reactants and products sides. So we need to balance it:
2Na + 2HCl —> 2NaCl + H2
That's better, it's balanced.
You will notice that this is not just a symbol equation but a balanced equation.
So, how did we balance it?
It all starts with H2 this is known as a diatomic molecule, meaning it can't exist on its own as a single hydrogen atom, so it joins to another hydrogen atom.
This will automatically mean that we would now have two hydrogen atoms on the products side of the equation, so we must double the number of hydrogen atoms on the reactants side.
Na + 2HCl —> NaCl + H2
You will notice that 2 was added in front of HCL that's because we cannot add another hydrogen to this compound. So we make two compounds of HCL instead, becoming 2HCL.
Because we have now doubled the compound, it now means we have two chlorines on the reactants side; so we now add a 2 in front of NaCl of the products side, becoming:
Na + 2HCl —> 2NaCl + H2
We are almost there, can you guess what we do now?
.
.
.
.
.
Yes, correct you will place a 2 in front of the Na on the reactants side as there was 2 in front of the NaCl on the product side when we balanced the Cl atoms.
Our final product becomes:
2Na + 2HCl —> 2NaCl + H2
Have an attempt at these questions (answers are provided on the worksheet)
So, let's take an example to look at:
sodium + hydrochloric acid —> sodium chloride + hydrogen
This is an example of a word equation.
Now, let's produce a symbol equation.
Na + HCl —> NaCl + H2
Buts is this a balanced equation?
No, it's not:
One thing we need to remember from page 1 was that you must have the same number of atoms on the reactants and products sides. So we need to balance it:
2Na + 2HCl —> 2NaCl + H2
That's better, it's balanced.
You will notice that this is not just a symbol equation but a balanced equation.
So, how did we balance it?
It all starts with H2 this is known as a diatomic molecule, meaning it can't exist on its own as a single hydrogen atom, so it joins to another hydrogen atom.
This will automatically mean that we would now have two hydrogen atoms on the products side of the equation, so we must double the number of hydrogen atoms on the reactants side.
Na + 2HCl —> NaCl + H2
You will notice that 2 was added in front of HCL that's because we cannot add another hydrogen to this compound. So we make two compounds of HCL instead, becoming 2HCL.
Because we have now doubled the compound, it now means we have two chlorines on the reactants side; so we now add a 2 in front of NaCl of the products side, becoming:
Na + 2HCl —> 2NaCl + H2
We are almost there, can you guess what we do now?
.
.
.
.
.
Yes, correct you will place a 2 in front of the Na on the reactants side as there was 2 in front of the NaCl on the product side when we balanced the Cl atoms.
Our final product becomes:
2Na + 2HCl —> 2NaCl + H2
Have an attempt at these questions (answers are provided on the worksheet)
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