Question

If 5.0 moles of propane react, how many molecules of water will be formed? c3h8(g)+5O2 (g) 3co2(g)+4H2 O(g)

Answer 1

`1.2044*10^(25)` molecules of water are produced ( assuming excess of oxygen )

STEP BY STEP EXPLANATION :

according to the given balanced equation ,

`C_(3)H_(8) (g) + 5O_(2) (g)` ⇒
`3CO_(2)(g)  + 4H_(2)O(g)`

we see that , 1 mole of
`C_(3) H_(8)` ( propane ) reacts with 5 moles of
`O_(2)` (oxygen) to give 3 moles of
`CO_(2)` ( carbon di oxide )

and 4 moles of
`H_(2) O` (water) respectively.

• 1 mole of
  `C_(3) H_(8)` reacts to give 4 moles of
  `H_(2) O`
• ∴ 5 moles of
  `C_(3) H_(8)` reacts to give '
  `x`' moles of
  `H_(2) O`

• using the property of direct propotions ,

`(1)/(4) = (5)/(x) \\x = 20`

this is the number of moles;

the number of molecules are :

`20*N_(a)` =
`20*6.022*10^(23)` =
`12.044*10^(24)=1.2044*10^(25)`

thus answer is :
`1.2044*10^(25)`