Acid-base related chemistry [closed]








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What is the function of silica, $\ce{SiO2}$ in the equation 
$$\ce{CaO + SiO2 -> CaSiO3}$$ 
 a) A basic oxide 
 b) A acidic oxide 
 c) A reducing agent 
 d) An oxidising agent


Please explain.




*Since this sounds like a [homework question](https://chemistry.meta.stackexchange.com/questions/141/how-do-i-ask-homework-questions-on-chemistry-stack-exchange/142#142), I will not provide a full solution!*


### Is $\ce{SiO2}$ an oxidizing or reducing agent in the reaction?


Figure out the oxidation state for the $\ce{Ca}$ and $\ce{Si}$ in the starting materials and the product. As a rule of thumb, consider the oxidation state of (-2) for $\ce{O}$. Unless peroxides are concerned, this works well.



> 
>  $$\ce{Ca^{(+2)}O + Si^{(+4)}O2 -> Ca^{(+2)}Si^{(+4)}O3}$$  
> 
>  Apparently, there is no change - this is not a redox reaction!
> 
> 
> 


### Is $\ce{SiO2}$ a basic or an acidic oxide?


* How are basic and acidic oxides defined?
* Are there any rules (of thumb) for the oxides of metals and non-metals?



> 
>  Metal oxides are usually **basic** oxides. These can be considered anhydrides of the corresponding metal hydroxides, $\ce{CaO}$ is a typical example: $\ce{CaO + H2O -> Ca(OH)2}$
>  What about $\ce{SiO2}$?
> 
> 
> 


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