For this problem, we use the Beer Lambert's Law. Its usual equation is:
A = ∈LC
where
A is the absorbance
∈ is the molar absorptivity
L is the path length
C is the concentration of the sample solution
As you notice, we only have to find the absorbance. But since we are not given with the molar absorptivity, we will have to use the modified equation that relates % transmittance to absorbance:
A = 2 - log(%T)
A = 2 - log(27.3)
A = 0.5638
Answer:
6.53g of K₂SO₄
Explanation:
Formula of the compound is K₂SO₄
Given parameters:
Volume of K₂SO₄ = 250mL = 250 x 10⁻³L
= 0.25L
Concentration of K₂SO₄ = 0.15M or 0. 15mol/L
Unknown:
Mass of K₂SO₄ =?
Methods:
We use the mole concept to solve this kind of problem.
>>First, we find the number of moles using the expression below:
Number of moles= concentration x volume
Solving for number of moles:
Number of moles = 0.25 x 01.5
= 0.0375mole
>>Secondly, we use the number of moles to find the mass of K₂SO₄ needed. This can be obtained using the expression below:
Mass(g) = number of moles x molar mass
Solving:
To find the molar mass of K₂SO₄, we must know the atomic mass of each element in the compound. This can be obtained using the periodic table.
For:
K = 39g
S = 32g
O = 16g
Molar mass of K₂SO₄ = (39x2) + 32 + (16x4)
= 78 +32 + 64
= 174g/mol
Using the expression:
Mass(g) = number of moles x molar mass
Mass of K₂SO₄ = 0.0375 x 174 = 6.53g
We have get the mass of gaseous water after evaporation in a closed container.
The mass of water vapor after evaporation is 5 grams.
In closed container, there is no exchange in mass from system to surrounding, only heat may exchange. The number of moles of water vapour remains unchanged as 5 gram water is heated in closed container.
Due to heating, liquid water gets evaporated and intermolecular distance between water molecules increases in gaseous state than liquid state and intermolecuar force of attraction decreases.
Randomness of molecules increases in gaseous state than liquid state.
Answer:
0.960 m
Explanation:
Given data
- Mass of the solute: 27.9 g
- Molar mass of the solute: 233.2 g/mol
- Mass of the solvent: 125.0 g = 0.1250 kg
First, we will calculate the moles of solute.
27.9 g × (1 mol/233.2 g) = 0.120 mol
The molality of the compound is:
m = moles of solute / kilograms of solvent
m = 0.120 mol / 0.1250 kg
m = 0.960 m
Strong acids provide more H+ in the aqueous solution than the weak acids. This excess amount of H+ conducts more electricity in the solution.
Explanation:
The strong acid provides more H+ ion whereas the weak acids produce less H+ in the aqueous solution resulting in less amount of electricity conduction in the solution.
Weak acid- lesser amount of H+ produced
Strong acid- greater amount of H+ ( proton) produced.
