Consider the reaction CH4(g) + 2O2(g)—> CO2(g)+2H2O(g) how many grams of methane should be burned in an excess of oxygen at STP to obtain 5.6 L of carbon dioxide?
2.0 g
4.0 g
16.0 g
32.0 g

Explanation:

CH₄(g) + 2O₂(g)—> CO₂(g)+2H₂O(g)

                                22.4 L

22.4 litre of CO₂ is formed by 1 mol of methane

5.6 litre of CO₂ will be formed by 5.6 / 224. mol of methane

= mole of methane required = .25 mol of methane

= .25 x 16 = 4 gram of methane  ( mol weight of methane = 16 gm )

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.