6) What is the picture below an example of?

The picture below is an example of a food chain.

Explanation:

The bug (can't tell which one by the picture) eats the grass, the frog eats the bug, the snake eats the frog, and the eagle eats the snake.

The heat produced by burning of 1.9 mole of methane gas will be 1691.38 kJ.

Explanation: Standard molar enthalpy of combustion is defined as the change when 1 mole of the hydrocarbon gets completely burnt in the presence of oxygen gas at standard temperature and pressure.

Equation for the combustion of methane gas is given by:

We are given standard molar enthalpy of combustion for methane gas = 890.2 kJ/mol

This is the heat required for 1 mole of a gas.

So, heat required for 1.9 moles of a gas = 890.2kJ/mol × 1.9mol = 1691.38 kJ