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 gas is NH₃.
H₂ doesn't dissolve readily in water, SO₂ gives an acidic solution in water.
The solid residue is Fe(OH)₂.
FeSO₄ and Na₂SO₄ are soluble in water.
The answer is C.
According to Diagram B, look at the 1600 elevation until you see the descending air line touches it. Then look down at the temperature at the bottom of the graph. It is between 0 degrees to 5 degrees.
The only number that is between that range is 2 degrees C.
Answer:
9.0 moles of CaO
Explanation:
We have the reaction equation as follows;
Fe2O3 + Ca3(PO4)2 -------> 2FePO4 + 3CaO
Now we know from the equation that;
1 mole of iron III oxide yields 3 moles of CaO
Therefore;
3 moles of iron III oxide yields 3 * 3/1
= 9.0 moles of CaO
Answer:
They both have the same number of atoms
Explanation:
The number that indicates the amount of particles in a compound is the Avogadro's number (NA).
It does not matter the mass of compound we have, If we have 1 mol we will be sure that we are talking about 6.02×10²³ particles
6.02×10²³ represents the amount of atoms in twelve grams of 12-pure carbon and it is considered a reference to measure the amount of all kinds of substances present in a given system.