A/S Chemistry mass of product: EVERYONE PLEASE READ

Some industrial plants, for example aluminium smelters, emit fluorides. In the past, there have been cases of fluoride pollution affecting the teeth and joints of cattle. The Union Carbide Corporation has invented a process for removing fluorides from waste gases. It involves the reaction:

Fluoride ion (F- ) + Charcoal (C) => Carbon tetrafluoride (CF4)

The product CF4, is harmless. The firm claims that 1 kg of charcoal will remove 6.3 kg of fluoride ion. Do you believe this claim? Explain your answer.

Reply 1

Helenia

OK:

to balance the equation, you need to have:

C + 4 F- --->CF4 + 4 e-

For the mass calculations, you are only concerned with the left side of that equation. Using RAMs,

12g of C would react with 4 x 19g of F- = 76g of F-.

divide by 12 (to get mass of F reacting with 1g of C)

1g C will react with 76/12 = 6.3g F-

here the answer is already obvious, but to keep the examiners happy, multiply back up to kg (by 1000)

1kg C will react with 6.3kg of F- so yes, the claim is true.