According to the octet rule, atoms tend to gain, lose, or share electrons until they are surrounded by__8__ valence electrons.
Molar mass CaCl₂ = 111.0 g/mol
number of moles:
n = mass of solute / molar mass
n = 85.3 / 111.0
n = 0.7684 moles of CaCl₂
M = n / V
0.788 M = <span>0.7684 / V
</span>
V = 0.7684 / 0.788
V = 0.97512 L
hope this helps!
Answer is: molality of urea is 5.84 m.
If we use 100 mL of solution:
d(solution) = 1.07 g/mL.
m(solution) = 1.07 g/mL · 100 mL.
m(solution) = 107 g.
ω(N₂H₄CO) = 26% ÷ 100% = 0.26.
m(N₂H₄CO) = m(solution) · ω(N₂H₄CO).
m(N₂H₄CO) = 107 g · 0.26.
m(N₂H₄CO) = 27.82 g.
1) calculate amount of urea:
n(N₂H₄CO) = m(N₂H₄CO) ÷ M(N₂H₄CO).
n(N₂H₄CO) = 27.82 g ÷ 60.06 g/mol.
n(N₂H₄CO) = 0.463 mol; amount of substance.
2) calculate mass of water:
m(H₂O) = 107 g - 27.82 g.
m(H₂O) = 79.18 g ÷ 1000 g/kg.
m(H₂O) = 0.07918 kg.
3) calculate molality:
b = n(N₂H₄CO) ÷ m(H₂O).
b = 0.463 mol ÷ 0.07918 kg.
b = 5.84 mol/kg.
Answer:
- 7.48
Explanation:
Given:
Concentration of the sugar solution, C = 0.3 M
Temperature, T = 27° C = 273 + 27 = 300 K
Now,
The solute potential is given as:
solute potential = - iCRT
where,
i is the number of particles the particular molecule will make in water
i = 1 for sugar
R is the universal gas constant = 0.0831 liter bar/mole-K
on substituting the respective values, we get
solute potential = - 1 × 0.3 × 0.0831 × 300
or
The solute potential = - 7.479 ≈ - 7.48
Answer:
(A) The work done by the system is -101.325J
(B) The workdone by the system is -90.75J
Explanation:
(A) Workdone = -PΔV
Given that A = 100cm2 = 0.01m2
distance d = 10cm = 0.1m
ΔV= Area × distance
ΔV= 0.01 ×0.1
ΔV = 0.001m3
P= external pressure = 1atm = 101325Pa
Workdone = -0.001 × 101325
W= - 101.325Pa m3
1Pam3 = 1J
Therefore W = - 101.325J
The work done on the system is -101.325J
(B) Workdone = -PΔV
Given that A = 50cm2 = 0.005m2
distance d = 15cm = 0.15m
ΔV= Area × distance
ΔV= 0.005×0.15
ΔV = 0.00075m3
P=121kPa = 121000Pa
W= - 121000 × 0.00075
W= -90.75Pa m3
1Pam3 = 1J
W = - 90.75J
The woekdone by the system is -90.75J
