Answer 1) : The density of the hot air inside the balloon can be found out by using ideal gas equation;
PV = nRT;
As n is number of moles and in gases, number of moles along with mass per mole is equal to the density of the gas.
If the moles in the gas are more the density will be more.
here, density (ρ) = mass (m) / volume (V); substituting in the ideal gas equation we get,
ρ = mP / RT
Answer 2) ρ (hot air) = ρ (cold air) X 
Here according to the formula because T(hot air) >T(cold air),
So, the density of hot air greater than the density of cold air.
The relationship between the ρ (h) = ρ(c) X
Answer:
0.00642mole
Explanation:
Molar Mass of Cu = 63.5g/mol
Mass of Cu from the question = 0.4076g
Number of mole =?
Number of mole = Mass /Molar Mass
Number of mole of Cu = 0.4076/63.5 = 0.00642mole
Answer:
CCl4 - Nonpolar
CH3OH - polar
NH3 - polar
CS2 - Nonpolar
Explanation:
One important thing that we should know is that polarity has to do with the presence of a resultant dipole moment in a molecule.
Dipole moment is a vector quantity, This means that its direction is also taken into account when discussing the dipole moment of molecules.
Hence, symmetrical molecules such as CS2 and CCl4 are non-polar even though they have polar bonds because their dipoles cancel out(zero resultant dipole moment).
On the other hand, NH3 and CH3OH are non-symmetrical molecules hence they possess an overall dipole moment and are polar molecules.
If there is a close container with some water, the following procedures take place.
Initially, the system contains only liquid, and air above it. As evaporation starts (the rate of evaporation is constant for the specific temperature of the water), the molecules from the surface of the liquid escape into vapour state, in the confined space above. Therefore, the level of liquid falls.
Then starts the process of condensation. This is the conversion of vapour into liquid. Initially, escaped molecules (from liquid state) move randomly in all directions and collide with one another. As more and more molecules enter the confined space, some slow-moving molecules are pushed back. They collide with the surface of the liquid to reconvert into liquid.
In the initial stages, the rate of evaporation (constant) is more than the rate of condensation because only small number of molecules are present in the gaseous state. The rate of condensation thereafter gradually increases as the number of molecules in the gaseous phase increases. Finally, a stage is reached when the rate of the two opposing processes is the same.
The state where the rate of evaporation becomes equal to the rate of condensation is called a state of dynamic equilibrium. In such a state, although the amount of liquid level in the container does not change, evaporation has not stopped and the system is not at rest. In fact, the number of molecules, which escape from the liquid to the gaseous phase (due to evaporation), becomes equal to the number of vapour molecules that return to the liquid
