Answer:
Grey precipitate implies the presence of silver ions
Yellow precipitate implies the presence of lead II ions
Explanation:
Qualitative analysis provides us a quick method of identifying ions present in a sample by chemical reactions involving simple reagents. Precipitates having a unique colour is formed. The identity of ions in the sample is deduced from the colour of precipitate obtained when particular reagents are added.
In the question, a precipitate containing silver ions upon standing turn into grey colour. Similarly, lead II ions give a yellow precipitate.
Answer: a) anode
b) positive
c) cathode
d) anode to cathode
Explanation:
Galvanic cell is defined as a device which is used for the conversion of the chemical energy produces in a redox reaction into the electrical energy.
In the galvanic cell, the oxidation occurs at an anode which is a negative electrode and the reduction occurs at the cathode which is a positive electrode. Thus the electrons are produced at anode and travel towards cathode.
Due to loss of electrons at anode, positive charge in concentrated in anode and negative charge is concentrated in cathode. To balance these charges , positive ions or cations from salt bridge move towards cathode and negative ions or anions from salt bridge move towards anode.
The balanced two-half reactions will be:
Oxidation half reaction :
Reduction half reaction :
Thus the overall reaction will be,