H-1 only has 1 proton and 1 electron, so its mass number is 1.
H-2 has one more neutron so its mass number is 2
H-3 has one more neutron than H-2 so its mass number will be 3.
average atomic mass = 1 x 99% + 2 x 0.8% + 3 x 0.2%
=1.012
Answer:
Distillation
Explanation:
Distillation is the process of separating the components of a liquid by using the method of selective boiling and condensation.
Since the components of the liquid have different boiling points, they would evaporate at different temperatures, thus causing the separation to occur.
So, distillation can be used to separate a mixture of milk and water.
Answer:
it means you have 4 sodium
Explanation:
We know that:
number of moles (n) = mass / molar mass
Now, from the general law of gases:
PV = nRT
where:
P is the pressure = 500 torr = 0.65 atm
V is the volume
n is the number of moles
R is the gas constant = 0.082
T is the temperature = 300 k
We will just rearrange this equation as follows:
P = nRT / V
Then we will substitute n with its equivalent equation mentioned at the beginning:
P = (mass x R x T) / (volume x molar mass) ......> equation I
Now, we know that:
density = mass / volume
We will substitute (mass/volume) in equation I with density as follows:
P = (density x R x T) / molar mass
Rearrange this equation to get the mass as follows:
molar mass = <span>dRT/P = (0.216 x 0.082 x 300) / 0.65 = 8.4738 grams
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From the periodic table:
molecular mass of hydrogen = 1 grams
molecular mass of nitrogen = 14 grams
Therefore:
molar mass of hydrogen = 2 x 1 = 2 grams
molar mass of nitrogen = 2 x 14 = 28 grams
We can assume that the number of moles of of each element is y.
We can thus build up the following equation:
2y + 28y = 8.4738
30y = 8.4738
y = 0.28246
Therefore:
mole fraction of hydrogen = 2 x 0.28246 = 0.56492
mole fraction of nitrogen = 28 x 0.28246 = 7.90888
Entropy is measure of disorder in system. Higher the disorder, greater the entropy.
Pair 1: NO2 (g) and N2O4 (g)
In the above case, entropy of N2O4 is more as compared to NO2, because N2O4 has more number of bonds as compared to NO2. So large number of vibrational energy levels are available for energy distribution which results in increasing entropy.
Pair 2: CH3OCH3(l) and CH3CH2OH(l)
Above compounds are structure isomers. They have same number of bonds and vibrational energy levels. However, presence of -OH group in CH3CH2OH results in intermolecular interaction via H bonding. This results in an ordered structure in CH3CH2OH as compared to CH3OCH3. Due to this entropy in CH3CH2OH is lower as compared to CH3OCH3.
Pair 3: HCl(g) and HBr(g)
In present case, HBr will have higher entropy as compared to HCl, because of larger number of sub-atomic particles in Br. Also, the higher molecular mass of HBr favors larger entropy.
