One of the half-reactions for the electrolysis of water is 2H+(aq) + 2e− → H2(g) If 0.845 L of H2 is collected at 25°C and 782 mmHg, how many faradays of electricity had to pass through the solution?

0.0725 faradays of electricity had to be passed through the solution.

Explanation:

Find how many hydrogen moles are produced.

1 mole of any gas consumes 24 liters at room temperature  

atmospheric pressure 1 environment is 760 mm Hg  

temperature is 25 deg C  

so if you reduced the pressure down to 760 mm Hg on that 0.845 liters you've gathered, you would discover the volume expanded to  

0.845 x 782/760 = 0.869 liters  

which equals to 0.0362 moles (divide by 24)  

since every atom of hydrogen required 2 electrons to be made, hence we need 0.0725 moles of electrons or 0.0725 faradays.

clouds form

solid ice forms on leaves.

water droplets form on grass.

they are made of gases.

they have a spherical shape.

they make energy through fusion.