For the equation [tex]BaCl _2+ Na _2 SO _4 \rightarrow BaSO _4+2 NaCl[/tex], how many chlorine atoms are on the reactants side and on the products side?
A. reactants: 1 ; products: 1
B. reactants: 1 ; products: 2
C. reactants: 2 ; products: 1
D. reactants: 2 ; products: 2
Answer (1)
Count the chlorine atoms on the reactants side: B a C l 2 has 2 chlorine atoms, N a 2 S O 4 has 0, totaling 2.
Count the chlorine atoms on the products side: B a S O 4 has 0 chlorine atoms, 2 N a Cl has 2, totaling 2.
Determine the number of chlorine atoms on each side.
The number of chlorine atoms on the reactants side and the products side is 2 ; 2 .
Explanation
Understanding the Problem We are given the chemical equation B a C l 2 + N a 2 S O 4 i g ha rro wB a S O 4 + 2 N a Cl and asked to determine the number of chlorine atoms on the reactants side and the products side.
Counting Reactant Chlorine Atoms On the reactants side, we have B a C l 2 + N a 2 S O 4 . The molecule B a C l 2 has 2 chlorine atoms, and N a 2 S O 4 has 0 chlorine atoms. Therefore, the total number of chlorine atoms on the reactants side is 2 + 0 = 2 .
Counting Product Chlorine Atoms On the products side, we have B a S O 4 + 2 N a Cl . The molecule B a S O 4 has 0 chlorine atoms, and 2 N a Cl has 2 × 1 = 2 chlorine atoms. Therefore, the total number of chlorine atoms on the products side is 0 + 2 = 2 .
Final Answer Thus, there are 2 chlorine atoms on the reactants side and 2 chlorine atoms on the products side.
Examples
In chemistry, balancing equations is crucial for determining the stoichiometry of a reaction, which helps in calculating the amounts of reactants needed and products formed. For instance, if you're synthesizing barium sulfate ( B a S O 4 ) from barium chloride ( B a C l 2 ) and sodium sulfate ( N a 2 S O 4 ), knowing the balanced equation B a C l 2 + N a 2 S O 4 → B a S O 4 + 2 N a Cl ensures you use the correct molar ratios to maximize product yield and minimize waste. This principle extends to various chemical processes, from drug synthesis to environmental remediation, where precise control over chemical reactions is essential.
