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

Answer:

$1.2044*10^{25}$ 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 ,

             $\frac{1}{4} = \frac{5}{x} \\x = 20$

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 : $1.2044*10^{25}$