Answer:
It changes by roughly 1 atm.
Explanation:
Hello!
In this case, since the ideal gas equation differs from the van der Waals' one by the presence of the a and b parameters which correct the assumption of no interactions into the container, they are written as:
Thus, the pressure via the ideal gas equation is:
And the pressure via the van der Waals equation, considering the molar volume (vm=0.200L/0.300L=0.667L/mol) is:
It means that the pressure change by 1 atm, which is not a significant difference for helium.
Each element or compound has a molar mass, which is calculated by multiplying the atomic mass of each element by the amount of atoms of that element, and summing the results of each element. The molar mass is measured in g/mol. So you divide the mass in grams by the molar mass to get the amount of moles.
Example:
There are 5g of water.
Calculate the amount of moles.
The water's formula is H2O, so the molar mass of it is
g/mol.
The amount of moles is:
5g ÷ 18g/mol ~ 0.28mol
Answer:
0.21 M. (2 sig. fig.)
Explanation:
The molarity of a solution is the number of moles of the solute in each liter of the solution. The unit for molarity is M. One M equals to one mole per liter.
How many moles of NaOH in the original solution?
,
where
.
What's the concentration of the diluted solution?
.
Concentration of the diluted solution:
.
The least significant number in the question comes with 2 sig. fig. Keep more sig. fig. than that in calculations but round the final result to 2 sig. fig. Hence the result: 0.021 M.