Respuesta :
AgNO₃ + (NH₄)₂CrO₄ ----> Ag₂CrO₄ + NH₄NO₃
This is a double replacement equation, so there is an ion exchange. So the easiest way to balance this equation is to separate the compounds into their ions.
AgNO₃ + (NH₄)₂CrO₄ ----> Ag₂CrO₄ + NH₄NO₃
Ag⁺ + NO₃⁻ + 2 NH₄⁺ + CrO₄²⁻ ----> 2 Ag⁺ + CrO₄²⁻ + NH₄⁺ + NO₃⁻
Usually we balance the elements, but it is easier in this case to balance the ions.
AgNO₃ + (NH₄)₂CrO₄ ----> Ag₂CrO₄ + NH₄NO₃
Ag⁺: 1 Ag⁺: 2
NO₃⁻: 1 NO₃⁻: 1
NH₄⁺: 2 NH₄⁺: 1
CrO₄²⁻: 1 CrO₄²⁻: 1
Let's start balancing the ion Ag⁺, we have two ions Ag⁺ on the right and only one on the left, so we have to change the coefficient in front of AgNO₃ and write a 2 there.
2 AgNO₃ + (NH₄)₂CrO₄ ----> Ag₂CrO₄ + NH₄NO₃
Ag⁺: 2 Ag⁺: 2
NO₃⁻: 2 NO₃⁻: 1
NH₄⁺: 2 NH₄⁺: 1
CrO₄²⁻: 1 CrO₄²⁻: 1
That change balanced the ion Ag⁺, but unbalanced the NO₃⁻. We have two on the left and only one on the right. We have to change the coefficient in front of NH₄NO₃ and write a 2 there.
2 AgNO₃ + (NH₄)₂CrO₄ ----> Ag₂CrO₄ + 2 NH₄NO₃
Ag⁺: 2 Ag⁺: 2
NO₃⁻: 2 NO₃⁻: 2
NH₄⁺: 2 NH₄⁺: 2
CrO₄²⁻: 1 CrO₄²⁻: 1
And finally our equation is balanced.
Answer: 2 AgNO₃ + (NH₄)₂CrO₄ ----> Ag₂CrO₄ + 2 NH₄NO₃
