We know that the number of moles HCl in 14.3mL of 0.1M HCl can be found by multiplying the volume (in L) by the concentration (in M).
(0.0143L HCl)x(0.1M HCl)=0.00143 moles HCl
Since HCl reacts with KOH in a one to one molar ratio (KOH+HCl⇒H₂O+KCl), the number of moles HCl used to neutralize KOH is the number of moles KOH. Therefore the 25mL solution had to contain 0.00143mol KOH.
To find the mass of KOH in the original mixture you have to divide the number of moles of KOH by the 0.025L to find the molarity of the KOH solution..
(0.00143mol KOH)/(0.025L)=0.0572M KOH
Since the morality does not change when you take some of the solution away, we know that the 250mL solution also had a molarity of 0.0572. That being said you can find the number of moles the mixture had by multiplying 0.0572M KOH by 0.250L to get the number of moles of KOH.
(0.0572M KOH)x(0.250L)=0.0143mol KOH
Now you can find the mass of the KOH by multiplying it by its molar mass of 56.1g/mol.
0.0143molx56.1g/mol=0.802g KOH
Finally you can calulate the percent KOH of the original mixture by dividing the mass of the KOH by 5g.
0.802g/5g=0.1604
the original mixture was 16% KOH
I hope this helps.
The impact that the oil spill has is environmental impacts.
Answer:
6.82g
0.59moles
Explanation:
1. What is the mass sample of 0.0500 moles of zinc chloride ?
Given parameters:
Number of moles ZnCl₂ = 0.05moles
Unknown:
Mass of the sample = ?
Solution:
To find the mass of a substance using the number of moles, it would be pertinent to understand what mole is.
A mole is a substance that contains the avogadro's number of particles.
It relates to the mass using the expression below;
Mass of a substance = number of moles x molar mass
Molar mass of ZnCl₂;
Atomic mass of Zn = 65.4g/mol
Cl = 35.5g/mol
Molar mass = 65.4 + 2(35.5) = 136.4g/mole
Mass of a substance = 0.05 x 136.4 = 6.82g
2. How many moles of potassium sulfide are in a 65.50g sample?
Given parameters:
Mass of K₂S = 65.5g
Unknown:
Number of moles = ?
Solution:
The number of moles of any substance is related to mass using the expression below;
Number of moles = 
Molar mass of K₂S = 2(39) + 32 = 110g/mol
Number of moles = 
= 0.59moles
Distillation is the <span>method that can be used to seperate parts of liquid mixture when the entire mixture can pass through a filter.</span>
