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Can you please help with part B? The vapor pressure of water changes with temper

ID: 514079 • Letter: C

Question

Can you please help with part B?

The vapor pressure of water changes with temperature, as shown here. A student designs an ammeter (a device that measures electrical current) that is based on the electrolysis of water into hydrogen and oxygen gases. When electrical current of unknown magnitude is run through the device for 4.00 min, 16.9 mL of water-saturated H_2 (g) is collected. The temperature and pressure of the system are 25 degree C and715 torr. How many moles of hydrogen gas are produced? Express your answer to three significant figures and include the appropriate units. 6.29 times 10^-4 mol Calculate the magnitude of the current in amperes if the number of moles of hydrogen gas produced is 6.29 times 10^-4 mol (from part A). Express your answer to three significant figures and include the appropriate units.

Explanation / Answer

According ot Faraday's first law of electrolysis,

W = M c t / Z F

W / M = c t / Z F

n = c t / Z F

c = Z F n / t

Substitute the given values from the data provided,

c = 4 * 96500 * 6.29 * 10-4 / (4.00 * 60)

c = 1.01 amp