Limestone added to water primarily increases which properties?

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Multiple Choice

Limestone added to water primarily increases which properties?

Limestone is calcium carbonate. When it dissolves in water, it releases calcium ions and carbonate species that buffer acidity, increasing the water’s alkalinity, and it also adds calcium, which raises hardness (specifically temporary or carbonate hardness). The dissolution reaction CaCO3 + CO2 + H2O ⇌ Ca2+ + 2HCO3− shows how bicarbonate forms to boost buffering capacity while calcium provides the hardness minerals. Because of this buffering effect, pH tends to rise or stabilize rather than drop, and turbidity remains low if the limestone fully dissolves. So limestone primarily increases alkalinity and hardness.

Limestone is calcium carbonate. When it dissolves in water, it releases calcium ions and carbonate species that buffer acidity, increasing the water’s alkalinity, and it also adds calcium, which raises hardness (specifically temporary or carbonate hardness). The dissolution reaction CaCO3 + CO2 + H2O ⇌ Ca2+ + 2HCO3− shows how bicarbonate forms to boost buffering capacity while calcium provides the hardness minerals. Because of this buffering effect, pH tends to rise or stabilize rather than drop, and turbidity remains low if the limestone fully dissolves. So limestone primarily increases alkalinity and hardness.

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