Question

How many grams of sodium hydroxide are needed to completely neutralize $25.0$ grams of sulfuric acid?

Answer 1

The stoichiometry of the reaction gives us an idea about the amount of reactant reacts in a particular ratio of mole or mass or number. The stoichiometry ratio of each and every reaction is fixed and it follows the Law of definite proportion or constant proportion.

Complete step by step answer:
During the chemical reaction, we follow the law of conservation of mass.
According to the law, during the chemical reaction, mass remains constant. i.e., mass of the reactant as well as mass of product are the same.
To follow the above law, we balance the chemical reaction in which we balance all the atoms included in the reactant as well as in the product.
A chemical reaction which contains more than one reactant to form a product, both reactants must combine in a definite ratio to form the product. Each and every reactant combines either in a fixed mole ratio or in a mass ratio to form a product.
Balanced chemical equation: -
${\operatorname{H} _2}S{O_4} + 2NaOH \to NaS{O_4} + 2{H_2}O$
In the above equation, both sulfuric acid and sodium hydroxide combine in a fixed mole ratio of $1:2$ to form sodium sulfate and two moles of water molecules.
The above reaction is balanced according to the Law of conservation of mass, where the mass of the reactant side is equal to the mass of the product side. According to the reaction, one mole of sulfuric acid combines with two moles of sodium hydroxide to form products.
In the given question, $25$ grams of sulfuric acid is given.
Gram molecular mass of sulfuric acid $= 98gram/mol,$
Gram molecular mass of sodium hydroxide $= 40gram/mol$
So according to the stoichiometry of the reaction
98 gram sulfuric acid reacts with $40$ gram of sodium hydroxide
So, $25$ grams of sulfuric acid completely react with $\dfrac{{25 \times 40}}{{98}}\,\, = \,10.20$gram sodium hydroxide
Final answer:
The final answer is $10.20$ gram of sodium hydroxide $(NaOH)$ is required to completely neutralized $25$ gram ${H_2}S{O_4}.$

Note:
In every reaction, atom conservation is very important. In any chemical reaction every time conservation of atom is there, by the help of atom conservation we can balance any chemical reaction.