Question: I need to write several formulas in CSS (or is there some other way?) and integrate it on my quiz website for students.

I already found some interesting examples in here:
<http://www.periodni.com/mathematical_and_chemical_equations_on_web.html>

But I need one more, as can be seen in this picture:

[![](https://i.stack.imgur.com/u7deK.gif)](http://www.docbrown.info/page15/Image166.gif)

Answer: 
I upvoted Nplay comment, easychem seems really fun.

Filthy, dirty way to achieve it with HTML (don't try this at home please) : 

```html
<p>
  <span style="visibility: hidden;">CH<sub>3</sub> - </span>CH<sub>3</sub><br/>
  <span style="visibility: hidden;">CH<sub>3</sub> - </span>|<br/>
  CH<sub>3</sub> - C - CH<sub>3</sub><br/>
  <span style="visibility: hidden;">CH<sub>3</sub> - </span>|<br/>
  <span style="visibility: hidden;">CH<sub>3</sub> - </span>CH<sub>3</sub><br/>
</p>
```
```
CO<sub>2</sub><br>
H<sub>2</sub> + O --->H<sub>2</sub>O

```

CO2  

H2 + O --->H2O