Question

based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation: ( )caso₄ → ( )o₂ + ( )cas

Explanation:

Step1: Analyze elements

First, list the number of each element on both sides. For Ca: left (CaSO₄) has 1, right (CaS) has 1. For S: left (CaSO₄) has 1, right (CaS) has 1. For O: left (CaSO₄) has 4, right (O₂) has 2 (per O₂ molecule).

Step2: Balance O

To balance O, we need 4 O on the right. Since each O₂ has 2 O, we need 2 O₂ molecules. Now check Ca and S: left CaSO₄: let's see the coefficients. Wait, the reaction is decomposition? Wait, CaSO₄ → O₂ + CaS. Wait, no, maybe oxidation - reduction? Wait, no, let's balance. Wait, CaSO₄ has 4 O, O₂ is diatomic. So for O: left 4, right 2x. So 2x = 4 → x = 2. Now, Ca: left 1 (from CaSO₄), right 1 (from CaS). S: left 1 (from CaSO₄), right 1 (from CaS). Wait, but the coefficient for CaSO₄: let's see, if we have 1 CaSO₄, then CaS is 1, O₂ is 2? Wait, no, wait the formula: CaSO₄ → O₂ + CaS. Wait, no, that can't be, because S in CaSO₄ is +6, in CaS is -2, so it's a redox reaction. Wait, maybe the reaction is 2CaSO₄ → 2CaS + 3O₂? No, wait, no, let's do it properly. Wait, no, maybe I made a mistake. Wait, the original equation: ( )CaSO₄ → ( )O₂ + ( )CaS. Let's assign coefficients: let a = coefficient of CaSO₄, b = O₂, c = CaS. Then: Ca: a = c; S: a = c; O: 4a = 2b. So from Ca and S, a = c. From O: 4a = 2b → 2a = b. Let's take a = 1, then c = 1, b = 2. So the equation is 1CaSO₄ → 2O₂ + 1CaS? Wait, no, that would mean O on right is 4 (22), left is 4 (14). Ca: 1 = 1, S: 1 = 1. Wait, but that would be a decomposition, but the oxidation states: S in CaSO₄ is +6, in CaS is -2, so S is reduced, O is oxidized (from -2 in SO₄²⁻ to 0 in O₂). So the number of electrons: S: +6 to -2, gain 8 e⁻ per S. O: -2 to 0, lose 2 e⁻ per O. So for each S, we need 4 O atoms (since 8 e⁻ gained, 2 e⁻ lost per O, so 8/2 = 4 O atoms, which is 2 O₂ molecules). So that matches a = 1, b = 2, c = 1. Wait, but let's check the equation: CaSO₄ → 2O₂ + CaS? No, 1CaSO₄ → 2O₂ + 1CaS? Wait, no, 1CaSO₄ has 4 O, 2O₂ has 4 O. Ca: 1 = 1, S: 1 = 1. So yes, that works. Wait, but that would be a redox reaction. So the coefficients are 1, 2, 1.

Answer:

The coefficients are 1 for CaSO₄, 2 for O₂, and 1 for CaS. So the blanks are filled with 1, 2, 1 respectively.