Answer:
The concentration is 0,2925M
Explanation:
We use the formula
C initial x V initial = C final x V final
11,7 M x 25 ml = C final x 1000 ml
C final= (11,7 M x 25 ml)/1000 ml = 0, 2925 M
(This formula applies to liquid solutions)
Answer:
ΔU=-369.2 kJ/mol.
Explanation:
We start from the equation:
Δ(H)=ΔU+Δ(PV), which is an extension of the well known relation: H=U+PV.
If Δ(PV) were calculated by ideal gas law,
PV=nRT
Δ(PV)=RTΔn.
Where Δn is the change of moles due to the reaction; but, this reaction does not give a moles change (Four moles of HCl produced from 4 moles of reactants), so Δ(PV)=0.
So, for this case, ΔH=ΔU.
The enthalpy of reaction given is for one mole of reactant, so the enthalpy of reaction for the reaction of interest must be multiplied by two:
ΔU=-369.2 kJ/mol.
From the equation, we can tell that 1 mol of Al₂S₃ requires 6 moles of water.
The molar ratio is 1/6
Moles of Al₂S₃ present = 20/150.17
= 0.133
Moles of water present = 2/18.02
= 0.111
The moles of Al₂S₃ that will react are:
0.111/6
= 0.0185
The remaining amount:
0.133 - 0.0185
= 0.1145 mol
Or
0.1145 * 150.17
= 17.19 grams
Answer:
E) molality
Explanation:
Molality -
Molarity of a substance , is the number of moles present in a Kg of solvent .
Hence , the formula for molality is given as follow -
m = n / s
m = molality
s = mass of solvent in Kg ,
n = moles of solute ,
Hence , from the given information of the question,
The concentration unit which have Kg of solvent , is molality.
