Is it true that water boils faster when it has salt in it?

Question

If it is true, why?

(I'm cooking spaghetti, I just thought of this question)

Answer 1

all the answers true unless you put a bigger burner under the pot.

Given the same heat input rate, yes, it should take 1+ 1C/(100C-20C) = 1.015 times as long with salt in the water.

Answer 2

Good question! So many people have the wrong info. when it comes to this.

For water at standard pressure (1 atmosphere), the boiling point occurs at 100°C , and the freezing point occurs at 0°C. A Liquid will boil when the vapor pressure is equal to the atmospheric pressure.

If we start with just barely boiling water and add some salt, the water will stop boiling.  The salt has lowered the vapor pressure of the solution.  To increase the pressure we need to add heat.  To add heat, we turn up the temperature.

It turns out that in the dilute solution case, the change in boiling temperature is proportional to the concentration of the added solute (salt).

Answer 3

nono actually it's quite the opposite. water boils slower when it has salt in it. boiling point elevation is a colligative property which means it depends on the amount of particles in solution, not the identity of the particles. water boils slower because with all the salt particles in the way it's kinda blocking the path of water molecules at the molecular level from escaping the solution so you actually need more energy or more heat to boil water when it contains salt.

Answer 4

Because the elements in salt form an ionic bond, the bond between the sodium and chloride ions are very strong, giving salt a high boiling point. So if there is salt in the water, it will take longer to reach the boiling temp.

Answer 5

Actually, the water boils slower.

This is because while the water tries to evaporate, the salt actually gets in the way of the evaporating water.

Answer 6

You have it backwards. Water boils slower when it has salt in it.

However the noodles taste better when you add a little salt and olive oil to your water. The EVOO also helps to keep the noodles slick so they won't stick together.  

Answer 7

no. the spaghetti actually cooks faster, because the water is able to reach temps above its normal boiling point of 100 C. it would take the water a longer time to reach a higher boiling point.