0
Calculate the average molar mass of dry air if it has a density of 1.17 gL at 21oC and 740.0 torr?
Wiki User
∙ 11y ago
29.13 g/mol
Wiki User
∙ 11y ago
Add your answer:
Earn +20 pts
What is the temp of a room?
around 21oC
What is the temp of a normal room?
around 21oC
What is the optimal air temperature in the home for good health?
21oC to 23oC
What is the coldest month in the Philippines?
The coldest month in the Philippines is January, with temperatures ranging from 21oC to 30oC.
Should schools have heating?
Absolutely ! In the UK it's a legal requirement to have offices, shops etc. heated to a minimum 21oC. That includes schools.
How hot is water at room temperature?
It is about 72 degrees F. if the temperature in the room is 72 degrees F. In other words, water at room temperature is generally somewhere near the temperature of the room.
Why is the bulb in a thermoniter important?
The bulb in a thermometer increases the sensitivity.When the temperature changes in the bulb, the mercury or other fluid will go up or down the narrow tube. The reason for this is due to change in the volume caused by expansion of the mercury or fluid; as the temperature increases, the volume increases.However, the change in volume may be very small, so by having a narrow tube, any movement caused by expansion will be more visually noticeable.To illustrate this, imagine two tubes containing 10ml of fluid each at 20oC. One tube is 1cm in diameter, the other 0.1cm. By using the equation for the volume of a cylinder we can calculate the height of the fluid in the tubes, (remember that 1ml = 1cm3)In 1cm diameter tube:Volume of fluid = pi x radius2 x height of fluid in tube10cm3 = pi x (0.5cm)2 x height of fluid in tubeHeight of fluid in tube = 10 / ( pi x 0.52 ) = 12.73cmIn 0.1cm diameter tube:Volume of fluid = pi x radius2 x height of fluid in tube10cm3 = pi x (0.05cm)2 x height of fluid in tubeHeight of fluid in tube = 10 / ( pi x 0.052 ) = 1273cmAs can be seen, the height of fluid in the smaller tube is much greater as the same amount of fluid has to fit into a smaller space. Now imagine that for a 1oC change in temperature the fluid expands 1% in volume. So at 21oC the 10ml of fluid expands 1% to 10.1ml (10ml x 1.01 (1%) = 10.1ml). Now we can calculate how much movement this would create in the tubesIn the 1cm diameter tube:Volume of fluid at 21oC = pi x radius2 x height of fluid in tube at 21oC10.1cm3 = pi x (0.5cm)2 x height of fluid in tube at 21oCHeight of fluid in tube at 21oC = 10.1 / ( pi x 0.52 ) = 12.86cmSo the fluid in the 1cm diameter tube has moved:Height at 20oC - Height at 21oC = Movement of fluid12.86cm - 12.73cm = 0.13cmWhilst in the 0.1cm diameter tube the fluid has moved:Height at 20oC - Height at 21oC (calculation not shown) = Movement of fluid1286cm - 1273cm = 13cmAs you can see, the movement in the smaller tube would be much more noticeable than in the larger tube and this would mean that even very small temperature changes could be visualised as the fluid moves a lot further. So that is why the central tube is so small, but why the bulb?In the example just shown both tubes had the same volume of starting fluid, 10ml. But, as you saw, 10ml in a 0.1cm diameter tube requires a tube of over 12 metres, a very impractical size for a thermometer! One way to solve this is to reduce the amount of starting fluid to 0.1ml.In the 0.1cm tube:Volume of fluid = pi x radius2 x height of fluid in tube0.1cm3 = pi x (0.05cm)2 x height of fluid in tubeHeight of fluid in tube = 0.1 / ( pi x 0.052 ) = 12.73cmNow we have a thermometer, which although large, could be used. But, look what happens when we increase the temperature to 21oC. The fluid expands to 0.101ml (=0.1ml + 1%) and the new height of fluid in the 0.1cm diameter tube is:Volume of fluid at 21oC = pi x radius2 x height of fluid in tube at 21oC0.101 cm3 = pi x (0.05cm)2 x height of fluid in tube at 21oCHeight of fluid in tube at 21oC = 0.101 / ( pi x 0.052 ) = 12.86cmThis gives a change in height from 20oC to 21oC of only 0.13cm. We have lost the sensitivity given by the smaller tube.Therefore, to make a sensitive thermometer we need a large volume and a narrow tube. So how do we do this without making a thermometer too big to use? By adding the bulb. The bulb is a lot wider than the narrow tube of the thermometer and is therefore able to hold a larger amount of mercury or fluid. But if the entire tube was the same width as the bulb, any expansion would be difficult to see. So by combining the bulb, with its ability to hold a large volume of mercury or fluid, with the narrow tube, with its ability to cause large movement of fluid for a small amount of expansion, we create a sensitive thermometer.So to give a short answer, the bulb increases sensitivity by increasing the volume of mercury or fluid inside the thermometer causing greater amplification of expansion, or movement, up the narrow tube. So more volume = greater movement = greater sensitivity.The bulb in a thermometer increases sensitivity. It helps determine whether the fluid will go up or down. The bulb helps make a sensitive thermometer and it helps in holding a larger amount of mercury or fluids than the narrow tube.
What does the expression mean cream puffs on a lower shelf?
That sounds like a cooking instruction for a non-fan oven. Without a fan there are temperature zones in a [gas] oven with the lower shelves at a lower temperature than the higher shelves. In a gas cooker, the setting for gas mark is [usually] the centre shelf; the top shelf is about 1 to 11/2 gas marks higher (about 25-37oF, 14-21oC hotter), the bottom shelf is about 1 to 11/2 gas marks lower (about 25-37oF, 14-21oC cooler) - the differences will be in the cooker's manufacturer's instructions. By putting the cream puffs of a lower shelf, they are baked at a lower temperature than that at which the oven has been set, allowing the baking of something else on a higher shelf at a higher temperature at the same time.
What is the temperature rang on Jupiter?
Temperature Range on JupiterThe temperature at the top of Jupiter's clouds is approximately -230oF (-145oC). The temperature increases as you move downward through the clouds, and reaches 70oF (21oC) at the point in the atmosphere where its atmospheric pressure is about 10 times that of earth's. Near the core of Jupiter the temperature may reach 43,000oF (24,000oC), which is hotter than the surface of the sun.Sources do not agree on what exactly the surface temperature of Jupiter is, perhaps because it is a gaseous planet that has no surface as we think of them. Most agree that the temperature is well under -100oF, and closer to -150oF at what is considered to be the surface.
How much heat is required to heat a 3.5 kg gold bar fro 21 c to 67 c?
First we need to know the specific heat, C, of gold, which is 0.129 J/g•oC. Then we use the equation q = m x C x (Tf - Ti), where q is the amount of heat energy gained or lost by a substance, m is the mass of sample in grams, Ti is the initial temperature, and Tf is the final temperature. 3.5kg must be converted to grams, which is 3500g.Solution:q = 3500g x 0.129 J/g•oC x (67oC - 21oC) = 20769 Joules = 21000 Joules rounded to 2 significant figures.
What to wear at 10 degrees?
You should wear at least a regular t-shirt, under a heavy jacket that is 100% waterproof, some fuzzy earmuffs, some mittens or finger gloves that are insulated well, some tough boots, tight sweatpants under some bigger jeans, and you will be able to stand and play outside for a while!Answer:In most of the world 10o is 10oC. This is essentially a cool basement temperature so a long sleeved shirt and pants will keep you comfortable for any amount of time.In America this may mean 10oF which is about -12oC , This is decidedly cool and requires a jacket, maybe light gloves. No long underwear or winter boots are required (unless there is deep snow). Being outside for a walk in the city between buildings would only require a sports jacket.Experimental Results:Today was -21oC (-5oF) with a windchill of -31oC, considerably cooler than the criteria of the question. People were observed to be wearing:Light winter jackets (usually unzipped)No glovesNo boots, just street shoesA few people wore tuques
What are the high and low temperatures on planet Uranus?
Temperature Range on JupiterThe temperature at the top of Jupiter's clouds is approximately -230oF (-145oC). The temperature increases as you move downward through the clouds, and reaches 70oF (21oC) at the point in the atmosphere where its atmospheric pressure is about 10 times that of earth's. Near the core of Jupiter the temperature may reach 43,000oF (24,000oC), which is hotter than the surface of the sun. Sources do not agree on what exactly the surface temperature of Jupiter is, perhaps because it is a gaseous planet that has no surface as we think of one. Most agree that the temperature is well under -100oF, and closer to -150oF at what is considered to be the surface.
