Q1: Pick out the wrong statement:

ANS:D - Pure copper is highly susceptible to stress corrosion.

1. Soft water is more corrosive than that carrying calcium salts.
   • This statement is generally true. Soft water, which lacks mineral ions like calcium and magnesium, can be more corrosive to certain metals and materials compared to hard water, which contains these ions. Soft water tends to be more aggressive in leaching ions from metals, potentially causing corrosion.
2. The corrosion of brass condenser tubes handling brine solution is also termed as 'dezincification'.
   • This statement is true. Dezincification refers to the selective removal of zinc from brass alloys, leaving behind a porous copper structure. It commonly occurs in brass components exposed to corrosive environments, such as those containing chloride ions in solutions like brine.
3. Non-annealed brass is highly susceptible to season cracking (i.e., inter-crystal corrosion due to internal stresses).
   • This statement is true. Non-annealed brass, which has not undergone annealing (a heat treatment process to relieve internal stresses and increase ductility), is indeed more susceptible to season cracking. Season cracking refers to the cracking of brass components due to internal stresses, especially when exposed to certain environmental conditions or corrosive agents.
4. Pure copper is highly susceptible to stress corrosion.
   • This statement is false. Pure copper is actually less susceptible to stress corrosion compared to many other metals. Stress corrosion is more commonly associated with materials like brass, aluminum alloys, and certain stainless steels, rather than pure copper. Pure copper is relatively resistant to stress corrosion due to its high ductility and lack of alloying elements that can promote such corrosion.

The wrong statement is: "Pure copper is highly susceptible to stress corrosion." Pure copper is actually less susceptible to stress corrosion compared to many other metals. Stress corrosion is more commonly associated with materials like brass, aluminum alloys, and certain stainless steels, rather than pure copper.