Question

Which equation for the reaction between sodium carbonate and dilute hydrochloric acid is correct?
A.$N{a_2}C{O_3}\left( s \right) + HCl\left( {aq} \right) \to NaCl\left( {aq} \right) + C{O_2}\left( g \right) + {H_2}O\left( l \right)$
B.$N{a_2}C{O_3}\left( s \right) + HCl\left( {aq} \right) \to N{a_2}Cl\left( {aq} \right) + C{O_2}\left( g \right) + {H_2}O\left( l \right)$
C.$N{a_2}C{O_3}\left( s \right) + 2HCl\left( {aq} \right) \to NaCl\left( {aq} \right) + C{O_2}\left( g \right) + {H_2}O\left( l \right)$
D.$N{a_2}C{O_3}\left( s \right) + 2HCl\left( {aq} \right) \to 2NaCl\left( {aq} \right) + C{O_2}\left( g \right) + {H_2}O\left( l \right)$

Answer 1

Hint: This question gives the knowledge about the double displacement reactions. Double displacement reactions are also known as metathesis reactions or double displacement or exchange reactions. This reaction involves exchanging ions.

Complete answer:
Double displacement reactions involve exchanging ions of reactants which leads to the formation of new products. Double displacement reactions are also known as metathesis reactions or double displacement or exchange reactions. Water is generally used as a solvent in double displacement reactions. In double displacement reactions a gas, a solid precipitate and a water molecule is formed as products as a result of switching of ions in the reactant side.
The general reaction or the general way to represent the double displacement reaction is as follows:
${A^ + }{B^ - } + {C^ + }{D^ - } \to {A^ + }{D^ - } + {C^ + }{B^ - }$
In the above reaction, the anions of the reactants get swapped and lead to the formation of products.
When sodium carbonate reacts with dilute hydrochloric acid, it leads to the formation of sodium chloride, water and emission of carbon dioxide with brisk effervescence. The reaction between sodium carbonate and dilute hydrochloric acid is as follows:
$N{a_2}C{O_3}\left( s \right) + HCl\left( {aq} \right) \to NaCl\left( {aq} \right) + C{O_2}\left( g \right) + {H_2}O\left( l \right)$
The reaction is not considered to be until and unless the number of reactants and products are balanced. The balanced chemical equation is defined as the equation in which the number of atoms in a molecule are equal in reactant and the product side.
$N{a_2}C{O_3}\left( s \right) + 2HCl\left( {aq} \right) \to 2NaCl\left( {aq} \right) + C{O_2}\left( g \right) + {H_2}O\left( l \right)$

Therefore, option D is correct.

Note: Always remember that the double displacement reactions are also known as metathesis reactions or double displacement or exchange reactions. In balanced chemical reactions, the number of atoms in a molecule are equal in reactant and the product side.