Microwaving Water!

[Guest guest]

Microwaving Water!

 

A 26-year old man decided to have a cup of coffee. He took a cup of water and

put it in the microwave to heat it up (something that he had done numerous times

before). I am not sure how long he set the timer for, but he wanted to bring the

water to a boil. When the timer shut the oven off, he removed the cup from the

oven. As he looked into the cup, he noted that the water was not boiling, but

suddenly the water in the cup 'blew up' into his face. The cup remained intact

until he threw it out of his hand, but all the water had flown out into his face

due to the build up of energy. His whole face is blistered and he has 1st and

2nd degree burns to his face which may leave scarring.

 

He also may have lost partial sight in his left eye. While at the hospital, the

doctor who was attending to him stated that this is a fairly common occurrence

and water (alone) should never be heated in a microwave oven. If water is heated

in this manner, something should be placed in the cup to diffuse the energy such

as a wooden stir stick, tea bag, etc.., (nothing metal).

 

General Electric's Response:

 

Thanks for contacting us, I will be happy to assist you. The e-mail that you

received is correct. Microwaved water and other liquids do not always bubble

when they reach the boiling point. They can actually get superheated and not

bubble at all. The superheated liquid will bubble up out of the cup when it is

moved or when something like a spoon or tea bag is put into it.

 

To prevent this from happening and causing injury, do not heat any liquid for

more than two minutes per cup. After heating, let the cup stand in the microwave

for thirty seconds! before moving it or adding anything into it.

 

Here is what our local science teacher had to say on the matter: 'Thanks for the

microwave warning. I have seen this happen before. It is caused by a phenomenon

known as super heating. It can occur anytime water is heated and will

particularly occur if the vessel that the water is heated in is new, or when

heating a small amount of water (less than half a cup).

 

What happens is that the water heats faster than the vapor bubbles can form. If

the cup is very new then it is unlikely to have small surface scratches inside

it that provide a place for the bubbles to form. As the bubbles cannot form and

release some of the heat has built up, the liquid does not boil, and the liquid

continues to heat up well past its boiling point.

 

What then usually happens is that the liquid is bumped or jarred, which is just

enough of a shock to cause the bubbles to rapidly form and expel the hot liquid.

The rapid formation of bubbles is also why a carbonated beverage spews when

opened after having been shaken.'

 

  you could very well save someone from a lot of pain and suffering. 

 

 

If you pass this on