A metal forms the fluoride MF3. Electrolysis of the molten fluo- ride by a current of 3.86 A for 16.2 minutes deposits 1.25 g of the metal. Calculate the molar mass of the metal.

Video transcript

everyone in this example, we're told that MBR three is a metal bromide salt. What is the molar mass Of the metal? If 2.56 g of the metal is deposited when NBR three undergoes electrolysis for 18.4 minutes and a 3.29 ampule current. So we're going to start out our solution by taking the time given in the prompt as 18. minutes And we're going to focus on getting rid of that unit minute by converting from minutes to seconds. So we should recall that in one minute. We have 60 seconds, we can cancel out minutes now. And now we're going to focus on converting from seconds to columns by Recalling that for one ampule, we have that equal to one column per second. And so that means we can interpret this current value as 3. columns per second, meaning that we can use that as a conversion factor. Where we have 3.29 columns for one second. So now we're able to cancel out seconds and now we're going to focus on converting from Columns two moles of electrons by recalling Faraday's constant, which you recall has a value of 96,485 columns for one mole of electrons. So now we're able to cancel our units of columns. And now we're going to focus on converting from moles of our electrons to moles of our metal. Now we should recognize that we have a coefficient of three in our metal bromide salt formula. And so that subscript of three, there corresponds to the transfer of three electrons. And that is due to the fact that we recognize that this metal bromide salt is a ionic compound which involves the transfer of electrons. So we can say that we have three moles of electrons transferred for one mole of our metal adam here. And so this would allow us to cancel out moles of electrons. And so now we're left with molds of our metal, which is what we want to calculate. And this here is going to give us a value equal to 0.01255 moles of our metal. So we can just say em And so next now we want to go ahead and calculate its molder mass. So according to the prompt, we have 2.56 g of our medal and we're going to divide this by the molds of our medal which we found above As 0.01255 moles of our metal. And so we have g per mole as our units. And what we're going to get is a value of about g per mole of our molar mass of our metal. And so this would be our final answer here as the molar mass of our metal according to our solution. So I hope that everything I explained was clear. If you have any questions, please leave them down below and I will see everyone in the next practice video.