B. A barrage stores water during high and low tides,when the water is released ,it turns the plant's turbine.
Answer: 
Explanation:
The balanced chemical reaction is,

The expression for Gibbs free energy change is,
![\Delta G_{rxn}=\sum [n\times \Delta G_(product)]-\sum [n\times \Delta G_(reactant)]](https://tex.z-dn.net/?f=%5CDelta%20G_%7Brxn%7D%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20G_%28product%29%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20G_%28reactant%29%5D)
![\Delta G_{rxn}=[(n_{CO_2}\times \Delta G_{CO_2})+(n_{CaO}\times \Delta G_{CaO})]-[(n_{CaCO_3}\times \Delta G_{CaCO_3})]](https://tex.z-dn.net/?f=%5CDelta%20G_%7Brxn%7D%3D%5B%28n_%7BCO_2%7D%5Ctimes%20%5CDelta%20G_%7BCO_2%7D%29%2B%28n_%7BCaO%7D%5Ctimes%20%5CDelta%20G_%7BCaO%7D%29%5D-%5B%28n_%7BCaCO_3%7D%5Ctimes%20%5CDelta%20G_%7BCaCO_3%7D%29%5D)
where,
n = number of moles
Now put all the given values in this expression, we get
![\Delta G_{rxn}=[(1\times -394.4)+(1\times -604.17)]-[(1\times -1128.76)]](https://tex.z-dn.net/?f=%5CDelta%20G_%7Brxn%7D%3D%5B%281%5Ctimes%20-394.4%29%2B%281%5Ctimes%20-604.17%29%5D-%5B%281%5Ctimes%20-1128.76%29%5D)

Therefore, the gibbs free energy for this reaction is, +130.19 kJ
Answer:
Ionic
Explanation:
If A does not have electron to bond, it just receives one electron from B.
It can´t be covalent because A don´t have any electrons to bond with B.