Why do cold glasses sweat

Water cannot pass through what we consider to be conventional glassware. However, there are special porous glass systems known as semi-permeable membranes which do allow for the transport of water molecules as well as other molecular species.

The Best Drinking Glass Our pick. Bormioli Rocco Rock Bar. The best drinking glass. Budget pick. Upgrade pick. Duralex Picardie. A more elegant all-purpose drinking glass. Also great. IKEA Godis. The best soda-lime glass. The best plastic tumbler. Dew is the result of water changing from a vapor to a liquid. This forces water vapor in the air around cooling objects to condense.

When condensation happens, small water droplets form — dew. The temperature at which dew forms is called the dew point. Simply put a sock over the bottom of the bottle. The sock will absorb the " sweat " and will also help keep your drink cold longer. During summer season, water vapor presented in the atmosphere is more due to high evaporation rating. This evaporation rating increases the content of water vapor. The water vapor will form a layer on the surface of the can.

This amount of water that can exist as a gas is measured as a pressure. It's called specifically, the vapour pressure. Originally Answered: Why does a cold glass of water leave a wet ring on the table? We say water "condenses" on the can and that water is called "condensation. The can is dehumidifying the air, not dehydrating as a reader stated. Dehydration removes water from things, but we don't use that for the atmosphere, only for objects.

This is why we say dehydrated food not dehumidified food, and why we have a device called a dehumidifier. If you place a coke can in a humid room, after the can has absorbed all of the energy it is able to, we say that the can has reached a state of equilibrium Honestly a can wouldn't be doing anything that could be described except for sitting somewhere.

The action is all in the air changing form. You could say the can looks condensed or looks like it's condensing. Sign up to join this community.

The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Cold containers don't sweat—what do they do? Ask Question. Asked 6 years, 3 months ago. Active 6 years, 3 months ago.

Viewed 3k times. Airplane wings are said to ice up when it is cold enough to that ice forms. So it seems the sweating and tearing metaphors harken back to a time when hydrology was misunderstood I don't mean dew , which is formed as the ambient air gradually cools to the dew point ; I mean the water that forms when warm air encounters a cooled object. Improve this question. Brian Hitchcock. Brian Hitchcock Brian Hitchcock You're right. The water is not coming from inside the can, so the phenomenon cannot accurately be called "sweating".

A small technicality. Dew forms in just the same way as the condensation you descibe: humid air is cooled to its dew point, when water condenses on the cool surface. There is no difference whatsoever. I am sorry that this elementary physics does not answer the original question.

So would this be localized dew? I have seen it on the big tin cans we call cars. Is "dew", in reference to cars, idiomatic? If you want to know what the phenomenon is commonly called you're in the right place, and the term is "sweating" at least in the US.

If you want to know what process causes this phenomenon, you should be asking in Physics SE , not here. When the sweat hits the air, the air makes it evaporate this means it turns from a liquid to a vapor. As the sweat evaporates off your skin, you cool down. Hot foods, oily foods, acids and alcohol cause Styrofoam food containers to partially break down, leaching styrene into whatever food the container is holding, according to a fact sheet on Styrofoam compiled by Northern Illinois University.

Skip to content Why does a cup sweat? Why does your soft drink can sweat more in the summer than during rainy days? What dewpoint means? Is water a vapor? Is sweat a condensation? Do foam cups sweat? Do 4 ounces of water as a liquid or 4 ounces of water as ice take up more space? At what temperature will condensation occur?

What happens to heat during condensation? Does condensation causes cooling? Why do I sweat so easily? Why do I sweat so much in high humidity? What kind of process is sweating?

What does a dew point of 70 mean? What level of humidity is uncomfortable? This water vapor is always present in the air, even on clear days. Grasping the water cycle at the point of condensation may help in recognizing how water forms on a cold glass.

In the water cycle, water vapor pushed into the cooler upper atmosphere slows the evaporation rate down to less than the rate of condensation.

Condensation occurs at a quicker rate, and the gaseous water molecules condense around tiny airborne particles of dust, salt and smoke to form tiny droplets that can grow by collecting more liquid water molecules. Similar to the cooler upper atmosphere, as the glass in our example from the beginning becomes cold from the ice in the drink, it reaches a temperature where condensation happens at a higher rate than evaporation.

Even on a hot day, and even though hot air can hold more water vapor than cold air, there is an upper limit to how much water vapor air can hold. The movement of particles can explain this increase in condensation rate. When the hot air comes in contact with the cold glass, heat is transferred from the hot air to the cold glass.

The loss of heat in the surrounding air causes the water vapor by the glass to lose energy. Once energy is lost, the water vapor condenses into liquid on the glass. Once the ice melts in the drink, the temperature of the liquid inside the glass and the surrounding air will come into equilibrium, and condensation on the glass will no longer be formed.