Answer:- Formula of the hydrate is 
and it's name is Iron(III)sulfate pentahydrate.
Solution:- As per the given information, there is 18.4% water in the hydrate. If we assume the mass of the hydrate as 100 grams then there would be 18.4 grams of water and 81.6 grams of Iron(III)sulfate present in the hydrate.
Molar mass for Iron(III)sulfate is 399.88 gram per mol and the molar mass for water is 18.02 gram per mol.
We will calculate the moles of Iron(III)sulfate and water present in the compound on dividing their grams by their molar masses as:
= 
= 
Now, the next step is to calculate the mol ratio and for this we divide the moles of each by the least one of them means whose moles are less. Here, the moles of Iron(III)sulfate are less than moles of water. So, we divide the moles of each by 0.204.
= 1
= 5
There is 1:5 mol ratio between Iron(III)sulfate and water. So, the formula of the hydrate is and the name of the hydrate is Iron(III)sulfate pentahydrate.
Answer:
75 mg
Explanation:
We can write the extraction formula as
x = m/[1 + (1/K)(Vaq/Vo)], where
x = mass extracted
m = total mass of solute
K = distribution coefficient
Vo = volume of organic layer
Vaq = volume of aqueous layer
Data:
m = 75 mg
K = 1.8
Vo = 0.90 mL
Vaq = 1.00 mL
Calculations:
For each extraction,
1 + (1/K)(Vaq/Vo) = 1 + (1/1.8)(1.00/0.90) = 1 + 0.62 = 1.62
x = m/1.62 = 0.618m
So, 61.8 % of the solute is extracted in each step.
In other words, 38.2 % of the solute remains.
Let r = the amount remaining after n extractions. Then
r = m(0.382)^n.
If n = 7,
r = 75(0.382)^7 = 75 × 0.001 18 = 0.088 mg
m = 75 - 0.088 = 75 mg
After seven extractions, 75 mg (99.999 %) of the solute will be extracted.
Answer:
Option C. +150KJ
Explanation:
Data obtained from the question include:
Heat of reactant (Hr) = 200KJ
Heat of product (Hp) = 350KJ
Change in enthalphy (ΔH) =..?
The enthalphy of the reaction can be obtained as follow:
Change in enthalphy (ΔH) = Heat of reactant (Hp) – Heat of reactant (Hr)
ΔH = Hp – Hr
ΔH = 350 – 200
ΔH = +150KJ
Therefore, the enthalphy for the reaction above is +150KJ
We can get the vapor pressure of the solution from this formula:
Pv(solu) = n P°v
when n is the mole fraction of toluene so we can get by substitution in this formula:
n = moles of toluene / (moles of cholesterol + moles of toluene)
= 5.4 / ( 0.99 + 5.4) = 0.85
so by substitution in vapor pressure formula:
∴ Pv(solu) = 0.85 *41 = 34.85 atm
Based on my knowledge of chemistry i think it’s D. I feel a little iffy on this question because i can see a lot of the choices being correct somehow but one of the more strict and essential points of my chemistry class was choice D
