Question 20.

Balance the following equation stepwise.

NaOH (aq) + H2SO4(aq) → Na2SO4(aq) + H2O(l)

Answer:

__Balanced equation:__ 2NaOH + H2SO4Na2SO4 + 2H2O

Explanation:

⇒ Step 1: Write the given unbalanced equation

NaOH + H2SO4Na2SO4 + H2O

⇒ Step 2: Compare the number of atoms of reactants with the number of atoms of products.

⇒ Step 3: Now, first we consider the element having unequal no. of atoms on both sides. Thus, let us consider sodium atom. If we multiply 2 in the reactant (in 2NaOH), we will get the equal number of atoms as in product (Na2SO4)

⇒ Step 4: Write the resulting equation:

2NaOH + H2SO4Na2SO4 + H2O

⇒ Step 5: Now check whether the equation is balanced or not by comparing the atoms

We find that the equation is not balanced yet. As the number of Oxygen, hydrogen and sulphur atoms are unequal on the two sides.

First balance the hydrogen number.

⇒ Step 6: Now, let us consider hydrogen atom. If we multiply 2 in the product (in H2O), we will get the equal number of atoms as in reactant (in 2NaOH and H2SO4))

⇒ Step 7: Write the resulting equation:

2NaOH + H2SO4Na2SO4 + 2H2O

⇒ Step 8: Now check whether the equation is balanced or not by comparing the atoms.

We find that the equation is now balanced yet.

⇒ Step 11: Write down the final balanced equation:

2NaOH + H2SO4Na2SO4 + 2H2O