To find the molarity of the NaOH solution, let's go through the calculations step by step:
Understanding the Fuel Cell Reaction:
The overall reaction for the hydrogen-oxygen fuel cell is:
2H2+O2⟶2H2OFrom this reaction, we see that 4 Faradays (F) of charge will produce 2 moles of water. One Faraday is approximately 96,500 Coulombs (C), so 4 F equals
4×96,500C.
Calculating Charge Passed:
The charge
(Q) is given by the current
(I) multiplied by the time
(t). Here, the current is 1 A , and the time is 595.1 hours. Convert this time into seconds:
‌t=595.1×60×60‌ seconds ‌‌Q=1×595.1×60×60=2,142,360CDetermine Water Produced:
Use the relationship between charge available and water produced:
‌ Water produced ‌=‌×2,142,360c≈200gThis is equivalent to 200 mL of water because the density of water is
1g∕mL.
Calculate Molarity of NaOH Solution:
The NaOH is dissolved in this water. We know:
Mass of
NaOH=5gMolar mass of
NaOH=40g∕molVolume of water in liters
=200‌mL=0.200LCalculate moles of NaOH :
‌ Moles of ‌NaOH=‌=0.125‌molFinally, calculate molarity:
‌ Molarity ‌=‌| ‌ moles of ‌NaOH |
| ‌ volume in liters ‌ |
=‌=0.625MThus, the molarity of the NaOH solution is 0.625 M .