CH4 + 202 → CO2 + 2H2O
How many grams of O2 needed to produce 36 grams of H2O?

Mass = 64 g

Explanation:

Given data:

Mass of water produced = 36 g

Mass of oxygen needed = ?

Solution:

Chemical equation:

CH₄ + 2O₂       CO₂ + 2H₂O

Number of moles of water produced:

Number of moles = mass/molar mass

Number of moles = 36 g/ 18 g/mol

Number of moles = 2 mol

Now we will compare the moles of water and oxygen.

             H₂O       :          O₂

                2         :           2

Mass of oxygen:

Mass = number of moles × molar mass

Mass =  2 mol × 32 g/mol

Mass = 64 g

gas

explanation:

smoke is the matter of a gas

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.