Why does salt water boil faster than plain water?

Answer 1

Because salt raises the temperature of the water so it reaches its boiling temperature faster.

Q: "Why does salt water boil more quickly than pure water"

A: "salt raise the temperature of the water"

Two remarks:1. The Q. is wrongly stated and should be corrected while answering (see below).2. The A. is a 'wrong' answer to 'another' Q.

"More quickly" means (in my opinion) 'at a lower temperature', thus water with salt boils at a HIGHER temperature than pure water (100 dgr.C).

This is because of the ions (+ and -) nesting in between the water molecules and add contraction forces between them.

(Cf. the addendum in the improved answer, below 2nd line)

Minor edit by another contributor: yeah, that's what I always thought too (that salt makes water take longer to boil). But I thought it was just me being an idiot again.

Higher boiling point

The answer to the question why do bubbles form when water is boiled? explains how, as the temperature of water rises, its molecules move around faster, collide more often and release more water vapor gas molecules. When the temperature reaches boiling point - about 100°C (212°F) - the pressure from the release of these molecules (the vapor pressure) becomes greater than atmospheric pressure and water vapor starts to escape as bubbles.

In salty water, Na+ and Cl- ions occupy some of the space between the water molecules. As temperature increases, although the water molecules are moving faster, there are less of them, so there are fewer collisions, less release of water vapor molecules and lower vapor pressure compared to pure water at the same temperature. It takes more energy (temperature) for the vapor pressure of salt water to reach and exceed atmospheric pressure and start to boil.

To raise the boiling point of one liter (34 ounces) of water by 1°C (1.8°F) requires about 58 grams (2 ounces) of salt. This is much more that the amount of salt typically added to boiling vegetables, which is done primarily for taste.

Answer 2

It Doesent The Project Is Quick And Easy, I Noticed That The Salt Took Longer Than Regular Boiling Water. The Salt Took More Than Ten Minutes Just To Boil. If a substance has a lower vapor pressure than the liquid It Will Start dissolving that substance in the liquid, common salt in water for Example, will lower the overall vapor pressure of the resulting solution compared with the pure liquid. A lower vapor pressure means that the solution has to be heated more than the pure liquid to make its molecules vaporize. It is an effect of the dilution of the solvent in the presence of a solute.

Answer 3

Whether water boils "sooner" depends on the amount of heat energy available to cause the water's temperature to rise to the boiling point. However, if heat is introduced at a constant rate into a specified amount of water and mixing is efficient enough for the water to have substantially uniform temperature throughout its volume, water that contains salt will boil later, not sooner, because the solute raises the minimum boiling temperature of the solution above that of pure water.

Answer 4

It doesn't. The presence of dissolved salt raises the boiling point of water resulting in it taking slightly longer to boil, all else being equal.

Answer 5

Because molecules of water are not as strongly bonded in salt water compared to regular water. So, you'll need lesser energy to boil it.

Answer 6

the when the water gets hott the NaCl breaks down and the ions separate

Answer 7

Salt does not make water boil faster. It makes it boil slower.

Answer 8

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