Answer:
For the first question, to determine the total number of molecules of nitrogen dioxide, first make use of the molar mass of the nonpolar compound and then use that to find the total number of moles and then subsequently after make use of the ratio for the Avogadro's number to determine the total number of molecules of this compound.
For the final question, do the inverse, where we make use of the molecules of the compound and then use Avogadro's number to determine the moles of the compound and then use the same molar mass of the compound to determine the grams of the Nitrogen Dioxide.
T=20 min
m₀=200 g
t=60 min
the mass of element through time t is:
m=m₀*2^(-t/T)
m=200*2^(-60/20)=25 g
25 grams of element will be left after 60 minutes
<h2>Answer:</h2>
<u>Temperature dependency is responsible for the process that hot water freeze faster than cold water.</u>
<h2>Explanation:</h2>
The effect given above is called Mpemba Effect. According to this idea hot water freezes more quickly as compared to cold water. But until now there is no convincing explanation for this strange phenomenon. One idea is that hot containers make better thermal contact with a refrigerator and so conduct heat more efficiently because a good conductor is good fro the transfer of heat. Another idea about this effect is that warm water evaporates more quickly and since this is an endothermic process, it cools the water making it freeze more quickly.