# Methane burns via the following reaction CH₄ + 2O₂ → CO₂ + 2H₂O. If 4.3 moles of CH₄ burn, how many moles of water form?

4.3 moles of methane will produce 8.6 moles of water.

To solve this, use a balanced chemical equation. The given equation is balanced. Then, determine the stoichiometric relation between species. 1 mole of methane will produce 2 moles of water, so to find the number of moles of water multiply the moles of methane by two.

To solve such questions, we have to use a balanced chemical equation.

A chemical equation or reaction is called balanced if the number of atoms of each element is equal on both sides of the reaction: the reactant side as well as the product side.

Let's check the given equation for the reaction between methane and oxygen resulting in the production of carbon dioxide and water.

`CH_4` + `2O_2` -> `CO_2` + `2H_2O`

To count the number of atoms of a given element, we need to look at the subscript associated with each atom as well as the number in front of the molecule itself. For example, for "`2O_2` ", the number of atoms of oxygen is 2 x 2 = 4 since the molecule O2 contains 2 atoms and there are 2 such molecules.

A quick check will tell you that there is 1 atom of carbon on each side of the equation, 4 atoms of hydrogen and 4 atoms of oxygen.

With a balanced equation, we can use stoichiometry to find a relationship between the number of molecules of each species.

Here, 1 mole of methane reacts with 2 moles of oxygen to produce 1 mole of carbon dioxide and 2 moles of water.

This relation is derived by using the number of molecules of each species in the balanced chemical equation.

Since 4.3 moles of methane are used in the reaction, it will react with 8.6 moles (2 x 4.3 = 8.6) of oxygen to produce 4.3 moles of carbon dioxide and 8.6 moles (2 x 4.3 = 8.6) of water.

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