The answer is B a yard hope this helps
Answer: The mass of 45.0 L of
at 87.0° C and 750 mm Hg is 56.605 g.
Explanation:
Given: Volume = 45.0 L
Temperature =
= (87.0 + 273) K = 360 K
Pressure = 750 mm Hg (1 mm Hg = 0.00131579 atm) = 0.98 atm
Formula used to calculate moles is as follows.
PV = nRT
where,
P = pressure
V = volume
n = no. of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.
![PV = nRT\\0.98 atm \times 45.0 L = n \times 0.0821 L atm/mol K \times 360 K\\n = \frac{0.98 atm \times 45.0 L}{0.0821 L atm/mol K \times 360 K}\\= \frac{44.1}{29.556} mol\\= 1.49 mol](https://tex.z-dn.net/?f=PV%20%3D%20nRT%5C%5C0.98%20atm%20%5Ctimes%2045.0%20L%20%3D%20n%20%5Ctimes%200.0821%20L%20atm%2Fmol%20K%20%20%5Ctimes%20360%20K%5C%5Cn%20%3D%20%5Cfrac%7B0.98%20atm%20%5Ctimes%2045.0%20L%7D%7B0.0821%20L%20atm%2Fmol%20K%20%20%5Ctimes%20360%20K%7D%5C%5C%3D%20%5Cfrac%7B44.1%7D%7B29.556%7D%20mol%5C%5C%3D%201.49%20mol)
Moles is the mass of a substance divided by its molar mass. So, mass of
(molar mass = 37.99 g/mol) is calculated as follows.
![Moles = \frac{mass}{molar mass}\\1.49 mol = \frac{mass}{37.99 g/mol}\\mass = 56.605 g](https://tex.z-dn.net/?f=Moles%20%3D%20%5Cfrac%7Bmass%7D%7Bmolar%20mass%7D%5C%5C1.49%20mol%20%3D%20%5Cfrac%7Bmass%7D%7B37.99%20g%2Fmol%7D%5C%5Cmass%20%3D%2056.605%20g)
Thus, we can conclude that the mass of 45.0 L of
at 87.0° C and 750 mm Hg is 56.605 g.
Answer: 5 water molecules
Explanation:
Decomposition of hydrated copper sulphate is given by:
![CuSO_4.xH_2O\rightarrow CuSO_4+xH_2O](https://tex.z-dn.net/?f=CuSO_4.xH_2O%5Crightarrow%20CuSO_4%2BxH_2O)
Molar mass of
= 159.6 g/mol
According to stoichiometry:
(159.6+18x) g of
decomposes to give = 159.6g of ![CuSO_4](https://tex.z-dn.net/?f=CuSO_4)
Thus 7.74 g of
decomposes to give=
g
But it is given 7.74 g of a sample of hydrated salt was found to contain 4.95 g of anhydrous salt.
Thus we can equate the two equations:
![\frac{159.6}{159.6+18x}\times 7.74=4.95](https://tex.z-dn.net/?f=%5Cfrac%7B159.6%7D%7B159.6%2B18x%7D%5Ctimes%207.74%3D4.95)
x=5
Thus there are 5 water molecules associated with each
formula unit.
Answer:
C - commas indicate a natural pause in the sentence
Answer:
Glass
Explanation: it has its atoms tightly bonded with each other