In the following three instances, which choice is greener in each situation? Explain. (a) Petroleum as a raw material or vegetable oil as a raw material. (b) Toluene as a solvent or water as a solvent. (c) Catalyzed reaction at $600 \mathrm{~K}\( or uncatalyzed reaction at \)800 \mathrm{~K}$.

To determine which raw material is greener, it is essential to consider the way they are produced or obtained, and their effect on the environment. Petroleum is a non-renewable resource, extracted from the Earth's crust through drilling, with potential to cause environmental problems such as oil spills, air and water pollution, and contributes to greenhouse gas emissions when used. Vegetable oil, on the other hand, is a renewable resource, derived from plants, which are grown, harvested, and processed to produce oil. This process has its own environmental impact, such as land-use change and water consumption. Considering the renewability, risks, and environmental consequences of each raw material, vegetable oil is greener than petroleum.

Toluene is a volatile organic compound (VOC) that contributes to air pollution, and its production is associated with higher energy consumption and environmental impact. It is also toxic to humans and the environment. Water is a renewable resource with low environmental impact during its production and use as a solvent. It does not contribute to air pollution and is generally non-toxic. Based on their environmental impact, water is a greener solvent compared to toluene.

A catalyzed reaction involves the use of a catalyst to reduce the activation energy required for a chemical reaction to occur, speeding up the reaction and allowing it to occur at lower temperatures. An uncatalyzed reaction occurs without a catalyst and may require higher temperatures for the reaction to take place. In general, lower temperatures translate to lower energy consumption, leading to a reduced environmental impact. Furthermore, using catalysts can lead to higher reaction efficiency, reducing the amount of waste generated during the reaction. Thus, a catalyzed reaction at 600K is greener than an uncatalyzed reaction at 800K.