Question

consider the equations. (1) ca(s) + co₂(g) + 1/2o₂(g) → caco₃(s) (2) 2ca(s) + o₂(g) → 2cao(s) how should you manipulate the equations so that they produce this equation when added? choose two correct answers. cao(s) → co₂(g) → caco₃(s) multiply equation (2) by 1/2 reverse the direction of equation (2) multiply equation (1) by 3

Explanation:

Step1: Analyze target equation

We want to get $CaO(s)+CO_2(g)\to CaCO_3(s)$ from the given equations.

Step2: Manipulate equation (2)

Equation (2) is $2Ca(s)+O_2(g)\to 2CaO(s)$. If we multiply it by $\frac{1}{2}$, we get $Ca(s)+\frac{1}{2}O_2(g)\to CaO(s)$. This gives us $CaO$ on the right - hand side as in the target equation.

Step3: Analyze equation (1)

Equation (1) is $Ca(s)+CO_2(g)+\frac{1}{2}O_2(g)\to CaCO_3(s)$. When we add the manipulated equation (2) (multiplied by $\frac{1}{2}$) to equation (1), we can get the target equation. Reversing equation (2) or multiplying equation (1) by 3 will not help in getting the target equation.

Answer:

multiply equation (2) by $\frac{1}{2}$