What is the freezing, melting, and boiling point of ketchup?

Question

Extra Credit for Science!!

Answer 1

Freezing point for standard Heinz ketchup is 26.4* F. there is no "melting point", as it is in a viscous state already. It can boil, however, at a mere 183* F

Answer 2

Ketchup is water with a bunch of dissolved solids in it (oh so good dissolved solids). There may be a bit of acetic acid (vinegar), but for the most part you can assume that it is just water. However, there are a few more effects that need to be taken into consideration:

Freezing and melting points are the same. However, the freezing point can be depressed depending on concentrations of various electrolytes. Hence, the freezing/melting point of ketchup would be slightly below 0 Celsius.

The boiling point is affected by surface tension which is affected by various electrolytes. Ionic substances increase the surface tension which in turn increases the boiling point. In the low concentrations of electrolytes that ketchup has, it can be assumed that it is still going to boil at 100 Celsius (give or take a degree).

As to the dissolved solids... they do not influence the boiling or freezing points directly. However, they will not turn to vapour like the water when the liquid boils. The viscosity of the mixture does not affect its boiling point. Water will still boil at 100 Celsius.

Summary: Ketchup freezes at 0 Celsius because it is mostly water. It Melts at the same temperature because of the same reason (and because the freezing point equals the melting point). The boiling point is 100 Celsius do to the same reason (mostly water).

Answer 3

The question you're asking is about the colligative properties of solutions. If we assume ketchup is a solution, the freezing point will be lower than that of water and the boiling point will be greater than that of water.

The amount that the freezing point (which is exactly equal to the melting point, by the way) changes is equal to the total concentration of solids multiplied by the cryoscopic constant (Kf), which for water is 1.8597 K kg/mol.

The amount that the boiling point changes is equal to the total concentration of solids multiplied by the ebullioscopic constant (Kb), which for water is 0.5129 K kg/mol.

To calculate the amount that the freezing point and melting point are decreased or the amount that the boiling point is increased is easy for simple solutions, but difficult for something like ketchup where you don't even know what all the chemical compounds in ketchup. Furthermore, these calculations really apply to dilute solutions, so they won't work out perfectly for ketchup.

What we can say is that the freezing point and melting point of ketchup are less than 32 degrees F (0 degrees C) and the boiling point of ketchup is higher than 212 degrees F (100 degrees C).

To do better than this, you'd actually have to perform an experiment and measure the freezing point/melting point and boiling point.

Answer 4

I would be the same as the freezing, melting, and boiling point for water, since this is the major component of kethcup. The tomatoes are over 75% water, and they add more water to the ketchup recipe to make it pourable. Ever see that clear, watery stuff run out of a bottle of ketchup if you don't shake it up first.

Answer 5

It is not the same as water as some have said. Pure water freezes at 32 and boils at 212. Most feezers are at about 20. Set it to 32 and see what happens to the food. It will melt. The sugars, proteins, oils, starches and other matter changes those numbers by a few degrees.

Answer 6

I think ketchup is a bit thicker, so freezing point should be 1-3 degree higher. But it should have the close boiling, freezing like water.

Answer 7

Ketchup has no boilin point!
Even among pure homogeneous substances there are those that don't have a melting, freezing, boiling point but a range. And ketchup is a heterogenous mixture.
It would be similar to asking what is the melting, boiling point of a cement.

Answer 8

From a chemical engineering perspective, you should assume that the ketchup is primarily a solution of salts in water. The tomato cell that make up a large part of the tomato paste used in ketchup do not really factor into the freezing and boiling points. Given this, you can consult a general-chemistry textbook (college or high school AP level) for the formula that gives the freezing/boiling point corrections for salt solutions in water.

If you want to guess what the salt concentrations are, a good way to start would be to take the mass of sodium in a given serving and multiply by 2.54 to get the total mass of NaCl salt, and to take the mass of potassium and multiply by 1.91 to get the mass of KCl salt. Assume that any carbohydrates and proteins are a part of the cell. Now, divide the total mass of NaCl and KCl by the mass of a given serving size (all of this is printed on the bottle), to get the mass ratio of salts vs. water. If the text asks for a molar or molal ratio, consult your periodic table for molecular weights.

Using the method above, you can approximate the freezing and boiling points of ketchup. Since you are dealing with a complex system, this isn't the best possible method, but it is better than assuming you are working with pure water. Another thing you could try is to simply boil and freeze ketchup, and make inferences about the degree that dissolved solids influence the system.

Another method, which is difficult to use for modeling complicated fluids like ketchup, would be to equate the liquid and vapor phase fugacities, and determine when the liquid phase fugacity reaches atmospheric pressure, which is a rough definition of the boiling point. For freezing, use solid and liquid phase fugacities. I do not think there are any data for a system like ketchup, so this will likely not be the best method for you to use. You could try modeling it as a water-salt-solid microparticle (solids being the tomato cells) system, if you do in fact want to try the fugacity route. Wikipedia has a good article on this, and is attached.

btw, I am a fourth-year chemical engineering student from GA Tech. This information came from memory of my AP Chem and Inorganic chemistry classes. The fugacity model comes from one of my thermodynamics classes, and is the basis for boiling-point calculations in chemical systems. However, it is typically only usable for 3-4 component systems, and becomes difficult to use after that.

Answer 9

Freezing/Melting Point is just below 32 degrees F or 0 degrees C.
Boiling Point is just above 212 degrees F or 100 degrees C. It actually depends on the amount of dissolved salts in the ketchup, which varies by manufacturer/recipe.

Answer 10

I would guess similar to water or salt water. Say 30 degrees F for freeze/melt, 212 F for boiling (since ketchup is mostly water). Not sure about the figures for catsup.

Answer 11

Freezing and melting point are the same - and would most likely freeze at/or near water's melting point (O deg C).

I would assume the water would boil off at 100C, and then the remaining components would remain as a solid residue.