# The reaction between methane and oxygen produces water and carbon dioxide. If 3.2g of methane reacts with 12.8g of oxygen, what is mass of water is the mass of CO2 is of 8.8g?

hkj1385 | (Level 1) Assistant Educator

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Molar mass of methane (CH4) = 16 g/mole

Molar mass of Oxygen (O2) = 32 g/mole

Molar mass of water (H2O) = 18 g/mole

Molar mass of Carbon Dioxide (CO2) = 44 g/mole

Now, the balanced reaction is :-

CH4(g) + 2O2(g)  ---------> CO2(g) + 2H2O(l)

Now, moles of CH4 reacting = mass of CH4/molar mass of CH4 = 3.2/16 = 0.2

Moles of O2 reacting = mass of O2/molar mass of O2 = 12.8/32 = 0.4

Now, As per the balanced reaction, for complete reaction to occur, one mole of CH4 require 2 moles of O2

Thus, 0.2 moles of CH4 requires 0.4 moles of O2

Clearly, both CH4 & O2 are present in the exact required quantity.

Hence, moles of CO2 formed = moles of CH4 reacted = 0.2

Mass of CO2 formed = moles of CO2*Molar mass of CO2 = 0.2*44 = 8.8 g

Moles of H2O formed = moles of O2 reacted = 2*moles of CH4 reacted = 0.4

Thus, mass of H2O formed = moles of H2O*molar mass of H2O = 0.4*18 = 7.2 g

giorgiana1976 | College Teacher | (Level 3) Valedictorian

Posted on

First, we'll write the reaction between methane and oxygen:

CH4 + O2 -> CO2 + 2H2O

To calculate the mass of a H2O, we'll use the formula:

Mass = moles*molar mass

The moles of H2O = 2*moles of CH4

We'll compute the moles of CH4:

Moles of CH4 = mass/molar mass = 3.2/16.4

Moles of CH4 = 0.200 mol

The moles of H2O = 2*0.200 = 0.400 mol

Now, we can identify the mass of H2O:Mass of H2O:

Mass of H2O = 0.400*18.2 = 7.2g

The requested mass of H2O resulted from reaction of 3.2g of methane with 12.8g of oxygen is 7.2g of H2O.