Tea kettle question.

[PsychoSerenity]

Can you boil an ocean with a cigarette lighter?

Again, you're talking extremes. I'm talking about a closed system with relatively similar amounts of mass to be heated.

To restate: Will 500 ml of hot water boil faster than 750 mi of hot water if all else is equal. If you add equal amounts of energy to both you get a higher total quantity of energy in the 750, yes?

Taking to extremes, the same principles apply, so you get the correct answer.

Yes the total quantity of energy in the 750 will be higher, but it will be spread out in a larger volume, so that higher level of energy will not raise the temperature as much.

[Gawdzilla Sama]

What if you don't make tea afterwards, is it still a tea kettle?

Actually, I'm using a Chernobyl-type containment vessel, but don't tell anybody.

[Xamonas Chegwé]

If you put 500 ml of hot water in a tea kettle will it heat to boiling faster than 750 ml of hot water?

Yes.

Assuming that the water is at the same temperature in both cases, ("hot" is not a temperature!) and that all other factors are the same (same atmospheric pressure, same kettle, same ambient temperature in the room, etc.) 50% more energy must be added to the larger volume in order to raise it to boiling point. The kettle's element (or the burner of the stove that it sits on, if it's an old-fashioned kettle) will deliver energy at the same rate in both cases, energy will be lost from the system at the same rate in both cases by radiation/conduction/convection (or rather, any difference will be negligible), hence, it will need to work 50% longer for the larger volume.

What if you don't make tea afterwards, is it still a tea kettle?

Considering we are talking about Zilla here, this becomes an extremely pertinent point!

[Gawdzilla Sama]

Okay, I gotta go to Washington, I'll be back in a few hours.

[FBM]

Can you boil an ocean with a cigarette lighter?

Again, you're talking extremes. I'm talking about a closed system with relatively similar amounts of mass to be heated.

To restate: Will 500 ml of hot water boil faster than 750 mi of hot water if all else is equal. If you add equal amounts of energy to both you get a higher total quantity of energy in the 750, yes?

The extreme demonstrates the principle, which can be applied reliably at a smaller scale. It's a common strategy in science. The differences in amounts of energy in the 750 and 500 ml samples will be proportionately identical to the differences in energy before you started heating. The larger sample has got a higher total energy content, but spread out through a greater volume, hence no faster boiling. When you apply the same heat to both samples, the smaller one boils faster because the heat has less volume of water to occupy. The molecules are subjected to a greater amount of excitation sooner and their bonds are broken sooner, which vaporizes them sooner.

If it were true that a larger volume of water had more energy and was therefore easier to boil, then it would be possible to have a volume of water great enough so that it would boil with very little or no energy added. But that doesn't happen.

[Gallstones2]

will this help????

Improve
The amount of energy to boil water depends on two things: the amount of water and the temperature of the water when you start.

The more water water, the more energy it takes. The colder the water, the more energy it takes.

Let say the water is at room temperature, or 20 °C. First, the water must be heated to 100 °C, which takes energy. The amount of energy is given by the specific heat of water, which is 4.186 Joule/gram °C. That means that requires 4.186 Joules of energy to heat 1 kilogram of water by 1 °C. So if you have 1 kilo grams of water at 20 °C, you have to add this much energy:

= (4.18Joule/gram °C) (100g) (100 °C - 20 °C)
= 334400 joules/°C
Of course, if you had more or less water, or it was colder or warmer, you would adjust this equation accordingly

[Xamonas Chegwé]

will this help????

Improve
The amount of energy to boil water depends on two things: the amount of water and the temperature of the water when you start.

The more water water, the more energy it takes. The colder the water, the more energy it takes.

Let say the water is at room temperature, or 20 °C. First, the water must be heated to 100 °C, which takes energy. The amount of energy is given by the specific heat of water, which is 4.186 Joule/gram °C. That means that requires 4.186 Joules of energy to heat 1 kilogram of water by 1 °C. So if you have 1 kilo grams of water at 20 °C, you have to add this much energy:

= (4.18Joule/gram °C) (100g) (100 °C - 20 °C)
= 334400 joules/°C
Of course, if you had more or less water, or it was colder or warmer, you would adjust this equation accordingly

You'd actually have to add quite a bit more - unless you had an entropy-proof kettle!

...and a teabag.

[FBM]

Another way of putting it: the vapor pressure of a larger volume of water is identical to the vapor pressure of the smaller volume, all else being the same. Heating the larger volume to its critical point requires more total energy and if the heat source for both small and large samples is the same, more time.

[Gallstones2]

yes can't forget the teabag ot tea leaves

[FBM]

I thought of yet another way of wording the answer to the OP: Yes.

[Xamonas Chegwé]

By the way, you should fill your kettle with COLD water, not hot! The kettle is a far more energy efficient method of heating small amounts of water than a household boiler!

[Gawdzilla Sama]

Okay, that's a good group answer to my question. Thanks to all.

By the way, you should fill your kettle with COLD water, not hot! The kettle is a far more energy efficient method of heating small amounts of water than a household boiler!

But you have to heat the cold water, yes? So if you start with hot water you save time? (Efficiency isn't that great an issue with 500 ml of water, I think.)

[JacksSmirkingRevenge]

Okay, that's a good group answer to my question. Thanks to all.

By the way, you should fill your kettle with COLD water, not hot! The kettle is a far more energy efficient method of heating small amounts of water than a household boiler!

But you have to heat the cold water, yes? So if you start with hot water you save time? (Efficiency isn't that great an issue with 500 ml of water, I think.)

...But you would already have wasted energy in heating the water in the boiler prior to putting some of it in the kettle. (-I think this is what XC was saying?)

PS - How long does it take to get a cup of fucking tea in your house?

[Gawdzilla Sama]

Okay, that's a good group answer to my question. Thanks to all.

By the way, you should fill your kettle with COLD water, not hot! The kettle is a far more energy efficient method of heating small amounts of water than a household boiler!

But you have to heat the cold water, yes? So if you start with hot water you save time? (Efficiency isn't that great an issue with 500 ml of water, I think.)

...But you would already have wasted energy in heating the water in the boiler prior to putting some of it in the kettle. (-I think this is what XC was saying?)

But the water's already heated in a reservoir system, one with a tank.

PS - How long does it take to get a cup of fucking tea in your house?

The issue is the time I spend in the kitchen waiting for the kettle to whistle.

[FBM]

The issue is the time I spend in the kitchen waiting for the kettle to whistle.

Less water, less wait.