Chemical effects of electric current

Q1) What is an atom?

Ans:An atom is an extremely small particle. It is made up of protons, neutrons, and electrons.

Q2) Differentiate between protons and electrons?

Ans:Protons are positively charged while neutrons do not have any charge. Electrons are presented in the space surrounding the nucleus of the atom. Electrons are negatively charged.

Q3) What is an anion?

Ans:Anions are negatively charged ions.

Q4) What charge does a cation carry?

Ans:Cations are positively charged ions.

Q5) Define ionization?

Ans: Ionisation is the process by which molecules break into cations and anions.

Q6) Give an example of an electrolytes?

Ans:Hydrochloric acid, sulphuric acid

Q7) Name a strong and a weak electrolyte.

Ans:Strong electrolyte: Nitric acid

Weak electrolyte: phosphoric acid

Q8) name the two electrodes in an elcetrolyte cell 

Ans: Anode and cathode

Q9) what is electrolysis?

Ans: The chemical change induced by the passage of electric current through electrolyte is known as electrolysis.

Q10) Mention one use of electroplating.

Ans: The purpose of electroplating is to coat a metal having a certain desired property such as wear resistance, corrosion protection, lubrication and aesthetic appeal .

Q11) Differentiate between anode and cathode?

Ans: The electrode connected to the positive terminal is the anode (positive electrode) and the electrode connected to negative terminal is the cathode.

Q12) what are conductors and insulators?

Ans: Some materials allow electricity to pass through them. Such materials are called conductors.

Materials that do not allow electricity to flow through them , such materials are called nonconductors of electricity or insulators.

Q13) What happens to common salt when it dissolves in water?

Ans: When table salt ( NaCl) dissolves in water, its molecules break into sodium ions and chloride ions. The sodium ions carry positive electric charge and the chloride ions carry negative electric charge.

Q14) why glucose a non-electrolysis?

Ans: Glucose and alcohol dissolve in water but do not form ions. Such compounds are called non-electrolysis.

All solutions that do not form ions do not conduct electricity.

Q15) why is sulphuric acid called an electrolyte?

Ans: A strong electrolyte is a compound such as Sulphuric acid that when dissolved in water ionizes completely. All its molecules break down to form cation and anions. Strong electrolytes are good conductor of electricity.

Q16) what is electroplating?

Ans: Electroplating is the process of deposition of a layer of one metal on top of another with the help of electric current.

Q17) Draw a labelled diagram to show that hydrochloric acid forms a strong electrolyte.

Ans:

Q18) Explain electrolysis of NaCl?

Ans: When table salt ( NaCl) dissolves in water, its molecules break into sodium ions ( Na⁺) and chloride ions ( Cl ^-) . the sodium ions carry positive electric charge and the chloride ions carry negative electric charge.

When a solution containing ions is subjected to electric current, the ions move . it is due to the movement of the ions that electric current flows through the solution. Thus ions conduct electric current through the solution. The more the number of ions present, the more the current that can be carried. Compounds such as common salt that dissolve in water and separate into ions, allow the conduction of electricity through the solution.

Q19) Explain with a suitable example the electroplating of a metal object.

Ans: The metal object which is to be electroplating is fixed in an electroplating chamber at the cathode.

The metal that is to be coated is made the anode. The chamber is then filled with an electrolyte which is generally the salt of the metal to be plated.

For example, in copper plating , a pure copper piece is fixed at the anode, the object to be plated with copper is fixed at the cathode and copper sulphat solution used as the electrolyte.

When the electric supply is switched on, the copper plate at the anode releases positively charged copper ions.

The copper ions move from the anode to the cathode through the solution and deposit on the metal object at the cathode. In copper electroplating, the electrolyte, copper sulphate solution remains unchanged.

Q20) Draw a labelled diagram of an electrolytic cell