Answer:
C a B r 2 ( a q ) + N a 2 S O 4 ( a q ) ⟶ 2 N a B r ( a q ) + C a S O 4 ( s )
Explanation:
A precipitation reaction involves a displacement process where a solid precipitate forms. This precipitate, being solid, is distinct from the other products and can be separated.
C a 2 + ( a q ) + S O 4 2 − ( a q ) ⟶ C a S O 4 ( s )
This equation is incorrect as it results in only C a S O 4.
C a B r 2 ( a q ) + N a 2 S O 4 ( a q ) ⟶ 2 N a B r ( a q ) + C a S O 4 ( s )
This is the proper reaction where C a S O 4 precipitate is produced.
C a 2 + ( a q ) + 2 B r − ( a q ) + 2 N a + ( a q ) + S O 4 2 − ( a q ) ⟶ 2 N a + ( a q ) + 2 B r − ( a q ) + C a S O 4 ( s )
This equation illustrates the ionic details of the precipitation reaction.
Calculation yields 209.53. The molar concentration is calculated by moles divided by volume. Given the volume of 750 mL, which translates to 0.75 L, the moles of CuBr₂ can be determined as molar concentration multiplied by volume, resulting in 1.25 × 0.75 = 0.9375. Mole count is derived from the mass of CuBr₂ divided by its molecular mass. The molecular mass of CuBr₂ is computed as 63.5 + 80 × 2 = 223.5, where the mass of Cu is 63.5 and that of Br is 80. Consequently, the mass needed amounts to 223.5 × 0.9375 = 209.53 g.
