hey, does anyone know the density of soap water?
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note: it's soap water, not soap.
your help is much appreciated. thanks in advance. (: -
What kinda soap?
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Secondary school science no teach how to find density?
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Soap water have less water tension on the surface.
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i have no time or the necessary materials to do an experiment now. i just need the right value for soap density right now. any kinda soap will do. actually, i just need to know if soap water is denser than pure water. a value would be better though.
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hey, could you tell me which website you saw that from?Originally posted by NotFromVenus:Soap water have less water tension on the surface.
if it's from a book or you can't remember the website, could you briefly tell me why soap water has less surface tension? -
Textbook got answer about whether pure stuff is denser or non-pure stuff is denser. It usually applies. Still no answer, there's always Google and Yahoo to help you.
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thanks for the help. i couldn't find it on google that's why i posted here.Originally posted by ndmmxiaomayi:Textbook got answer about whether pure stuff is denser or non-pure stuff is denser. It usually applies. Still no answer, there's always Google and Yahoo to help you.
do you have any idea how salt and soap affects surface tension? -
i saw that website too; unfortunately the value is for soap, not soap water.Originally posted by ^tamago^: -
"A bubble can exist because the surface layer of a liquid (usually water) has a certain surface tension, which causes the layer to behave somewhat like an elastic sheet. However, a bubble made with a pure liquid alone is not stable and a dissolved surfactant such as soap is needed to stabilise a bubble. A common misconception is that soap increases the water's surface tension. Actually soap does the exact opposite, decreasing it to approximately one third the surface tension of pure water. Soap does not strengthen bubbles, it stabilizes them, via an action known as the Marangoni effect. As the soap film stretches, the surface concentration of soap decreases, which causes the surface tension to increase. Thus, soap selectively strengthens the weakest parts of the bubble and tends to prevent them from stretching further. In addition, the soap reduces evaporation so the bubbles last longer, although this effect is relatively small.Originally posted by jenn_y:hey, could you tell me which website you saw that from?
if it's from a book or you can't remember the website, could you briefly tell me why soap water has less surface tension?
Their spherical shape is also caused by surface tension. The tension causes the bubble to form a sphere, as a sphere has the smallest possible surface area for a given volume. This shape can be visibly distorted by air currents, and hence by blowing. If a bubble is left to sink in still air, however, it remains very nearly spherical, more so for example than the typical cartoon depiction of a raindrop. When a sinking body has reached its terminal velocity, the drag force acting on it is equal to its weight, and since a bubble's weight is much smaller in relation to its size than a raindrop's, its shape is distorted much less. (The surface tension opposing the distortion is similar in the two cases: The soap reduces the water's surface tension to approximately one third, but it is effectively doubled since the film has an inner and an outer surface.)"
http://en.wikipedia.org/wiki/Soap_bubble
now i wonder if u geninuely need help in finding ur answer, or u just can't be bothered to google. -
http://www.elmhurst.edu/~chm/vchembook/554soap.htmlOriginally posted by jenn_y:thanks for the help. i couldn't find it on google that's why i posted here.
do you have any idea how salt and soap affects surface tension? -
you can do an experiment by putting an ant on the water in a cup, see how it walks on the water , Then drop a drop of soapy water onto the water .
You may wish to find out more about surface tension of liquid than probe on density if this is the topics you are actually looking at. -
i don't this part: As the soap film stretches, the surface concentration of soap decreases, which causes the surface tension to increase.... which is the only part that explains why soap increases surface tension. could anyone please explain this part to me?Originally posted by ^tamago^:"A bubble can exist because the surface layer of a liquid (usually water) has a certain surface tension, which causes the layer to behave somewhat like an elastic sheet. However, a bubble made with a pure liquid alone is not stable and a dissolved surfactant such as soap is needed to stabilise a bubble. A common misconception is that soap increases the water's surface tension. Actually soap does the exact opposite, decreasing it to approximately one third the surface tension of pure water. Soap does not strengthen bubbles, it stabilizes them, via an action known as the Marangoni effect. As the soap film stretches, the surface concentration of soap decreases, which causes the surface tension to increase. Thus, soap selectively strengthens the weakest parts of the bubble and tends to prevent them from stretching further. In addition, the soap reduces evaporation so the bubbles last longer, although this effect is relatively small.
Their spherical shape is also caused by surface tension. The tension causes the bubble to form a sphere, as a sphere has the smallest possible surface area for a given volume. This shape can be visibly distorted by air currents, and hence by blowing. If a bubble is left to sink in still air, however, it remains very nearly spherical, more so for example than the typical cartoon depiction of a raindrop. When a sinking body has reached its terminal velocity, the drag force acting on it is equal to its weight, and since a bubble's weight is much smaller in relation to its size than a raindrop's, its shape is distorted much less. (The surface tension opposing the distortion is similar in the two cases: The soap reduces the water's surface tension to approximately one third, but it is effectively doubled since the film has an inner and an outer surface.)" http://en.wikipedia.org/wiki/Soap_bubble
now i wonder if u geninuely need help in finding ur answer, or u just can't be bothered to google. -
so many maids helping the TS -
thought that's for soap water?Originally posted by jenn_y:i saw that website too; unfortunately the value is for soap, not soap water. -
You already said the answer yourself.Originally posted by jenn_y:i don't this part: As the soap film stretches, the surface concentration of soap decreases, which causes the surface tension to increase.... which is the only part that explains why soap increases surface tension. could anyone please explain this part to me? -
actually i've read all the website you guys gave me. what i really need to know is HOW the addition of soap and salt respectively decreases and increases the surface tension of water. can't seem to find it on the net.
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it says clearly that it's soap...not soap water?Originally posted by ^tamago^:thought that's for soap water? -
i dun understand what it means.Originally posted by ndmmxiaomayi:You already said the answer yourself. -
"As the soap film stretches, the surface concentration of soap decreases, which causes the surface tension to increase. Thus, soap selectively strengthens the weakest parts of the bubble and tends to prevent them from stretching further. In addition, the soap reduces evaporation so the bubbles last longer, although this effect is relatively small."Originally posted by jenn_y:i don't this part: As the soap film stretches, the surface concentration of soap decreases, which causes the surface tension to increase.... which is the only part that explains why soap increases surface tension. could anyone please explain this part to me?
it's like dissolving. the same amount of soap particle is being stretched out over a larger area, so the surface concentration of soap decreases.
increase of surface tension is best illustrated by the example of an ballon undergoing inflation.
by right this means the surface tension is higher, but if u read the previous paragraph, u'll understand why it didn't contrary to what is explained in the quoted sentence above. -
OH, OOPS. xP gah i overlooked it. THANKS!Originally posted by ^tamago^:thought that's for soap water? -
go consult ur lecturer...................................
