What would of happened if you used 20.g of substrate?

If you used 20 g of substrate instead of a different amount, the outcome would depend on the specific context, such as the type of reaction or process involved. Generally, using more substrate could lead to increased product yield, provided that the reaction conditions and catalysts are suitable. However, it may also result in potential issues like substrate inhibition or depletion of catalysts. Ultimately, the specific effects would vary based on the nature of the experiment or process being conducted.