Electrolysis and reduced mass of a metal bar

[Medicol]

1. Insert a bar of copper of m(gram) into (HCl + H2O). After a while, its weight become m_1 (gram) which is smaller than m. Explain why and give a general formula to find m_1



2. None



3. I keep thinking how that becomes possible, because I learn that Cu can't react with HCl+H2O

 

[Borek]

Question states "electrolysis", you are thinking in terms of dissolution.

 

[Medicol]

Question states "electrolysis", you are thinking in terms of dissolution.

my exercise is in Cu and Electrolysis chapter, I don't know how to explain why Cu's weight is lost over a short time.

 

[Borek]

Then read the chapter, it explains what reactions take place on the electrode during electrolysis.

 

[DeeNos]

.

1. The reduced mass of the copper bar is due to the process of electrolysis. When the copper bar is immersed in the HCl + H2O solution, a chemical reaction takes place at the surface of the bar. This reaction causes the copper atoms to lose electrons, forming positively charged ions. These ions then migrate towards the negative electrode, where they gain electrons and become neutral copper atoms again. This process of losing and gaining electrons results in the reduction of the mass of the copper bar.

The general formula to find m_1 would be: m_1 = m - (n * e), where m is the initial mass of the copper bar, n is the number of electrons lost by each copper atom, and e is the mass of one electron.

2. It is not possible for Cu to react with HCl + H2O. The electrolysis process does not involve a direct reaction between the copper and the solution. Instead, it involves the movement of ions within the solution and the transfer of electrons between the electrodes. Therefore, the copper bar remains unchanged chemically, but its mass is reduced due to the loss of electrons.

3. It is important to understand that electrolysis is a process that involves the movement of charged particles (ions) and the transfer of electrons, rather than a direct chemical reaction between the metal and the solution. This is a common misconception about electrolysis. The reduction in mass of the copper bar is a result of the transfer of electrons and not a chemical reaction.