Which of the following chemical equations violates the law of conservation of mass?

• A. 2H_2 + O_2 \rightarrow 2H_2O
• B. C + O_2 \rightarrow CO_2
• C. Na + Cl_2 \rightarrow 2NaCl
• D. 2K + Br_2 \rightarrow 2KBr

Answer: (C)

Verified step by step guidance

1. Recall that the law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction, so the number of atoms of each element must be the same on both sides of the equation.
2. Examine each chemical equation by counting the number of atoms of each element on the reactant side and on the product side.
3. For the equation \$2H_2 + O_2 \rightarrow 2H_2O$, count hydrogen and oxygen atoms on both sides to verify if they are balanced.
4. For the equation \(C + O_2 \rightarrow CO_2\), count carbon and oxygen atoms on both sides to check for balance.
5. For the equation \(Na + Cl_2 \rightarrow 2NaCl\), count sodium and chlorine atoms on both sides to see if the equation is balanced or violates the conservation of mass.