Write two principles of green chemistry.

Answer: (any two)

1. Prevention of waste: It is better to prevent the formation of waste than to treat or clean it up after it is formed.
2. Atom economy: Synthetic methods should be designed so that the maximum number of atoms of the reactants are incorporated into the final product.
3. Safer solvents and auxiliaries: Use of hazardous solvents and other auxiliary substances should be avoided; safer solvents such as water should be used.
4. Use of catalysts: Catalytic reagents, which are selective and are not consumed, are better than stoichiometric reagents.