Which of the following mixture is known as producer gas?

carbon monoxide and nitrogen 

The correct answer is option 3. carbon monoxide and nitrogen.

Producer gas is a fuel gas mixture that is typically obtained by the partial combustion of solid fuels, such as coal or biomass, in the presence of a controlled amount of air or oxygen. The main components of producer gas are carbon monoxide (CO) and nitrogen (N₂), along with other minor gases.

Here is an explanation of the key components:

1. Carbon Monoxide (CO):

Carbon monoxide is a colorless and odorless gas. In the context of producer gas, CO is a major component resulting from the incomplete combustion of carbonaceous materials. It is a combustible gas and can be used as a fuel.

2. Nitrogen (N₂):

Nitrogen is a major component of the Earth's atmosphere, making up about 78% of the air. When solid fuels are partially combusted to produce producer gas, nitrogen from the air is introduced into the mixture. Nitrogen is generally inert in combustion processes and does not participate in the combustion reactions.

3. Other Gases:

Depending on the specific conditions of the gasification process, other gases such as hydrogen (H₂), methane (CH₄), carbon dioxide (CO₂), and small amounts of tars and other hydrocarbons may also be present in producer gas.

4. Applications:

Producer gas has been historically used as a fuel for various applications, including heating, industrial processes, and power generation. It has been employed in gas engines and gasifiers to produce energy from solid fuels.

It's important to note that the composition of producer gas can vary depending on factors such as the type of fuel used, the air-to-fuel ratio, and the gasification process. While carbon monoxide and nitrogen are primary components, the presence of other gases depends on the specific conditions of the gasification.