Answer:
1.39
Explanation:
[Hg2Cl2]= 1M
[H^+] = ????
E°cell= 0.35V
E= 0.268 V
Therefore E for the reaction must -0.082 V
n= 2 moles of electrons
From Nernst Equation:
E= E°cell- 0.0592/n log [Red]/[Ox]
0.0268= 0.35- 0.0592/2 log 1/[Ox]^2
-0.082= -0.0296 log 1/[Ox]^2
log 1/[Ox]^2= 0.082/0.0296
log 1/[Ox]^2= 2.77
1/[Ox]^2=Antilog (2.77)
[Ox]^2=1.698×10^-3
[Ox] = 0.0412 M
But pH= -log [H^+]= -log(0.0412)= 1.385
Answer: 66.2 g
Explanation:
1) The ratio of Al in the molecule is 1 mol to 1 mol .
2) The mass of 1 mol of molecules of Al (CH2H3O2)3 is the molar mass of the compound.
3) You calculate the molar mass of the compound using the atomic masses of each atom, in this way:
Al: 27 g/mol
C: 2 * 3 * 12 g/mol = 72 g/mol
H: 3 * 3 * 1 g/mol = 9 g/mol
O: 2 * 3 * 16 g/mol = 96 g/mol
Molar mass = 27 g/mol + 72 g/mol + 9 g/mol + 96 g/mol = 204 g/mol
4) Set a proportion:
27 g/mol x
-------------------- = ----------
204 g/mol 500 g
5) Solve for x:
x = 500 g * 27 g/mol / 204 g/mol = 66.2 g
Answer:
6.4 × 10^-10 M
Explanation:
The molar solubility of the ions in a compound can be calculated from the Ksp (solubility constant).
CaF2 will dissociate as follows:
CaF2 ⇌Ca2+ + 2F-
1 mole of Calcium ion (x)
2 moles of fluorine ion (2x)
NaF will also dissociate as follows:
NaF ⇌ Na+ + F-
Where Na+ = 0.25M
F- = 0.25M
The total concentration of fluoride ion in the solution is (2x + 0.25M), however, due to common ion effect i.e. 2x<0.25, 2x can be neglected. This means that concentration of fluoride ion will be 0.25M
Ksp = {Ca2+}{F-}^2
Ksp = {x}{0.25}^2
4.0 × 10^-11 = 0.25^2 × x
4.0 × 10^-11 = 0.0625x
x = 4.0 × 10^-11 ÷ 6.25 × 10^-2
x = 4/6.25 × 10^ (-11+2)
x = 0.64 × 10^-9
x = 6.4 × 10^-10
Therefore, the molar solubility of CaF2 in NaF solution is 6.4 × 10^-10M
Answer:
0.9 moles of water
Explanation:
Use mole ratios:
5 : 6
divide by 5 on both sides
1 : 1.2
multiply by 0.75 on both sides
0.75 : 0.9
So the result is 0.9 moles of water
(Please correct me if I'm wrong)
Osmotic pressure is the pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution by osmosis.
That can be mathematical computed from the expression:
Osmotic pressure=C×R×T
Where,
C= Concentration
R=Gas constant
T=Temperature
Concentration=Number of moles of solute/Volume(L)
=0.005*1000/100
=0.05
R= 0.08206 atm L/mol K
T=25+273
=298
Osmotic pressure= 0.05×0.08206×298
=1.2 atm
