Why is water often referred to as NaCl (salt water), even though it may contain sulphates and phosphates too?

 

❓ Why is water often referred to as NaCl (salt water), even though it may contain sulphates and phosphates too?

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✅ 1. NaCl is the dominant and most recognisable salt in water

• In natural water bodies like oceans, rivers, and even groundwater, many dissolved minerals and salts are present.

• Sodium chloride (NaCl) is the most abundant salt in most of these, especially in seawater, which contains about 85–90% NaCl out of all dissolved salts.

• That’s why, when we casually refer to salt water, we usually mean water rich in NaCl.

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⚗️ 2. Other salts like sulphates and phosphates are present but in smaller amounts

• Sulfates (SO₄²⁻), phosphates (PO₄³⁻), magnesium, calcium, and nitrates are also present in water — but in much smaller concentrations.

• For example, seawater has:

  • Na⁺ and Cl⁻ (sodium and chloride) – ~90%

  • Mg²⁺, Ca²⁺, K⁺ – 10%

  • Sulfates, carbonates, bromides – trace amounts

  • Phosphates – very small amounts (usually in parts per million or less)

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3. NaCl is chemically simple and easy to represent

• NaCl (table salt) dissolves fully into Na⁺ and Cl⁻ ions, making it ideal for scientific study and reference.

• It's often used in labs and textbooks to explain conductivity, osmosis, and ionic solutions, even if real water has a more complex mix.

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Summary:

Reason	Explanation
Most abundant	NaCl is the main salt in seawater and many brackish water sources
Easy to represent	Chemically simple and commonly understood by everyone
Others are minor	Sulphates and phosphates exist, but in much smaller amounts
Conventional usage	"Salt water" often just means “NaCl-rich water” for general understanding