Question

When 4.2g of sodium hydrogen carbonate (\[NaHC{{O}_{3}}\]) is added to a solution of HCl weighing 10.0g, it is observed that 2.2g of \[C{{O}_{2}}\] is released into the atmosphere. The residue left behind is found to weigh 12.0g. Show that these observations are in agreement with the laws of conservation of mass.

Answer 1

Hint: The law of conservation of mass is useful for a number of calculations and can be used to solve for unknown masses, such as the amount of gas consumed or produced during a reaction.

Complete step by step solution:

Law of conservation of mass states that mass can neither be created nor be destroyed but it can only be transformed from one form to another. Mass remains conserved in a chemical reaction i.e. total mass on the reactant side is always equal to the total mass on the product side.
Now in the given question, according to the law of conservation of mass.
\[NaHC{{O}_{3}}\,+\,HCl\,=\,C{{O}_{2}}\,+\,residue\]
4.2 + 10 = 2.2 + 12
14.2 = 14.2
Total mass on the reactant side = 14.2g
Total mass on the product side = 14.2g

Therefore, we can see it is in agreement with the laws of conservation of mass.

Note: The law of conservation of mass is very important to the study and production of chemical reactions. If scientists will know the quantities and identities of reactants for a particular reaction, they can easily predict the amounts of products that will be made. Chemical manufacturers can increase their efficiency by applying the law of conservation of mass to their laboratory practices.