1.8 g
Given:
0.80 g of methane reacts with 3.2 g of oxygen to produce 2.2 g of carbon dioxide.
Question:
What mass of water is formed?
The Process:
Methane and oxygen react to form carbon dioxide and water. Remember this, the chemical activity that uses oxygen to produce light and heat is also called the combustion process.
In any chemical reaction, the sum of the masses of the reactants is equal to the sum of the masses of the products. That's right, this is called conservation of the masses.
Let us write the word equation of the chemical reaction and then solve the problem following the law of the conservation of mass.
[tex]\boxed{ \ Methane + Oxygen \rightarrow Carbon \ dioxide + Water\ }[/tex]
[tex]\boxed{ \ 0.80 \ g \ + \ 3.2 \ g \rightarrow 2.2 \ g \ + \ m_{Water}? \ }[/tex]
[tex]\boxed{ \ m_{reactants} = m_{products} \ }[/tex]
[tex]\boxed{ \ 0.80 \ g \ + \ 3.2 \ g = 2.2 \ g \ + \ m_{Water} \ }[/tex]
Rewrite by rearranging as follows:
[tex]\boxed{ \ 2.2 \ g \ + \ m_{Water} = 0.80 \ g \ + \ 3.2 \ g \ }[/tex]
[tex]\boxed{ \ 2.2 \ g \ + \ m_{Water} = 4.0 \ g \ }[/tex]
[tex]\boxed{ \ m_{Water} = 4.0 \ g - 2.2 \ g \ }[/tex]
Thus the mass of water formed is 1.8 g.
The balanced equation with state symbols is:
[tex]\boxed{ \ CH_4_{(g)} + 2O_2_{(g)} \rightarrow CO_2_{(g)} + 2H_2O_{(l)} \ }[/tex]
Notes:
Keywords: methane and oxygen, react to form carbon dioxide and water, combustion, to produce, the conservation of mass, the word equation, the balanced equation, Lavoisier
