Electrochemistry Test - 14

According to the first law of electrolysis the mass of of substance liberated at cathode is proportional to the quantity of electric charge passed through it or indirectly it's proportional to the quantity of  electricity  passed. 

$$H^+ +e^-\rightarrow \frac {1}{2}H_2; E_H=\frac {1}{2}\times 2=1;$$
$$Cu^{2+} +2e^-\rightarrow Cu; E_{Cu}=\frac {63.5}{2}=31.75$$
$$\frac {W_{Cu}}{E_{Cu}}=\frac {W_H}{E_H}$$ or $$W_{Cu}=\frac {0.504}{1}\times 31.75=16 g$$

An electric battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Each cell contains a positive terminal, or cathode, and a negative terminal, or anode. Electrolytes allow ions to move between the electrodes and terminals, which allows current to flow out of the battery to perform work.
Cell convert chemical energy directly to electrical energy. Redox reactions power the battery. Cations are reduced (electrons are added) at the cathode during charging, while anions are oxidized (electrons are removed) at the anode during discharge. The electrodes do not touch each other, but are electrically connected by the electrolyte. A separator allows ions to flow between electrodes, but prevents mixing of the electrolytes.
The voltage developed across a cell's terminals depends on the energy release of the chemical reactions of its electrodes and electrolyte. 
Hence, the chemical energy is converted into electrical energy.

In electrolytes, the charge carriers are ions, atoms that have gained electrons so they are negatively charged are called anions, atoms that have lost electrons so they are positively charged are called cations. Thus, ions are charged particles (e.g. Na+ sodium ion or Cl- chloride ion in NaCl solution) and their movement or flow constitutes an electric current, i.e. the electrolyte consists of a stream of moving charged particles.
Hence, in electrolytes, current is carried by both + ve and - ve ions.

As unlike charges attract each other and like charges repel each other. Thus in electrolysis, positive ions move towards the negative electrode whereas negative ions move toward the positive electrode.Hence option B is correct.

Resistivity is reciprocal of specific conductance (k).

The current inside a copper voltameter is the same as the outside value.An electric current is a flow of electric charge. In electric circuits this charge is often carried by moving electrons in a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in an ionised gas (plasma).Electric current is measured using a device called an ammeter.

Whenever copper sulfate or CuSO4 is added to water, it gets dissolved in the water. As the CuSO4 is an electrolyte, it splits into $${ Cu }^{ ++ }$$ (cation) and $${ { SO }_{ 4 } }^{ -- }$$ (anion) ions and move freely in the solution. Now if two copper electrodes are immersed in that solution, the $${ Cu }^{ ++ }$$  ions (cation) will be attracted towards cathode i.e. the electrode connected to the negative terminal of the battery . On reaching on the cathode, each $${ Cu }^{ ++ }$$  ion will take electrons from it and becomes neutral copper atoms. Similarly the $${ { SO }_{ 4 } }^{ -- }$$ (anion) ions will be attracted by anode i.e. the electrode connected to the positive terminal of the battery . So $${ { SO }_{ 4 } }^{ -- }$$ ions will move towards anode where they give up two electrons and become $${ SO }_{ 4 }$$ radical but since $${ SO }_{ 4 }$$ radical can not exist in the electrical neutral state, it will attack copper anode and will form copper sulfate.
Hence, When electric current is passed through the copper sulfate solution, free copper ions gets drawn to the electrode connected to the negative terminal of the battery and gets deposited on it.

On electrolysis, water splits up into its constituent ions as positively charged $$H^+$$ ions and negatively charged $$O^{-2}$$ ions.