Question

By using hard water, the Caustic embrittlement in boilers take place mainly due to the

formation of ______

Option A: - H2SO4
Option B: - NaOH

Option C: - HCl
Option D: - NH4OH​

Answer 1

Answer:

By using hard water, caustic formation takes place mainly due to the formation of salt precipitates such calcium carbonate, magnesium cabornate or by NaOH (Option B) formation.

Explanation:

Defination of Caustic embrittlement:

This is the process by which accumulation of caustic substances causes boilers to become brittle.

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Caustic embrittlement can be caused by either of the following ways:

1) In the case where hard water is used in boilers directly, caustic embrittlement is caused by salts such as CaCO₃, MgCl₂, MgCO₃ and CaCl₂.

In this way, these salts precipitate in the boilers when water evaporates and form either sludge or scale which makes the boiler material brittle

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2) The other way, is when hard water is softened first.

Water in industries is usually softened by Sodium Carbonate (Na₂CO₃). This salt usually remains as residues in the water.

When the water in boilers evaporate, the sodium carbonate concentration increases.

The Na₂CO₃ is then hydrolysed in the boilers by water to form NaOH.

The Equation:

Na₂CO₃ + H2O → 2NaOH + CO₂

It is this NaOH that is responsible for causing the boilers to embrittle.

The NaOH, in dissolved form, infiltrates into the the walls of the boilers by capillary action and accumulates in there.

The NaOH dissolves the wall by reacting with the metal, making it brittle.

Answer 2

Answer:

The answer to your question is B - NaOH.

Explanation:

• NaOH is sodium hydroxide, which is also commonly known as caustic soda, soda lime or lye.
• It is an inorganic compound that is a base and is widely used in the manufacturing of soaps.
• So, by using hard water, the Caustic embrittlement in boilers take place mainly due to the formation of NaOH.