Chemistry Questions and Answers

In electro-valency the oxidation number of the participating metal increases.

Yes, Toluene is used in making explosives, based on information from the textbook "New School Chemistry", pg 541.

Phenol is used as a starting material to makes explosive materials such as picric acid. Picric acid is one of the most acidic phenol. Like other strongly nitrated organic compounds, picric acid is an explosive. Toluene, however, is used to produce a stronger explosive material called TriNitroToluene (TNT).

Therefore Toluene is the most appropriate answer for this question but in situations where you don't find Toluene in the options provided, then Phenol makes a viable answer.

During the electrolysis of copper using platinum electrode, Cu and H migrate to the cathode while,SO$_4$ and OH migrate to the anode.CU is then discharged preferentially at the cathode, acquiring two electrons and is deposited as metallic copper, while OH is discharged preferentially at the anode and deposited as gaseous oxygen, then the SO$_4$ and H still in the solution react, thereby making d solution acidic and then changing the litmus paper red which is the test for acids.

The conductivity of a solution depends on the number of charge carriers (the concentrations of the ions), the mobility of the charge carriers and their charge. Theoretically, conductivity should increase in direct proportion to concentration.

Tap water contains less Ca$^{2+}$ and Mg$^{2+}$