Answer:
She will need to add 5.6 cups of water
Explanation:
Hi there!
Marta has to dilute the citric acid to 5%.
The dilution factor will be 12%/ 5% = 2.4. Then, Marta will need to dilute the citric acid 2.4 times. If she has 4 cups of the solution, she will need to add water until she completes a volume of (4 cups ·2.4) 9.6 cups to reach the desired concentration.
Then, she will need to add 9.6 - 4 cups water = 5.6 cups of water
Another way to solve this is by using the fact that the mass of citric acid in the concentrated and diluted solution is the same. Then:
mass citric acid concentrated solution = mass citric acid in dilute solution
mass of citric acid = concentration · volume
Then:
initial concentration · volume = final concentration · volume
12% · 4 cups = 5% · volume
volume = 12% · 4 cups / 5% = 9.6 cups
The final volume of the solution at 5% will be 9.6 cups. So Marta will need 9.6 cups - 4 cups = 5.6 cups water
Answer:
A; 
Explanation:
The best way to start solving this problem is to start with the molecule with the most atoms. Since there are 12 carbons on the left, you need 12 on the right so 12 would need to be placed in front of carbon dioxide. Also you need 22 hydrogens and in each molecule of water, there are two hydrogen molecules so you need 11 molecules of water. After balancing you find that you need 24 oxygen on the left so you place the coeffecient 12 in front of the oxygen molecule.
3KOH + H₃PO₄ ----> K₃PO₄ + 3H₂O
3 moles 1 mole
3 moles KOH ------ 1 mole H₃PO₄
X moles KOH ------ 1,56 mol
X = 3×1,56
X = 4,68 moles of KOH
:)
Answer:
VP as function of time => VP(Ar) > VP(Ne) > VP(He).
Explanation:
Effusion rate of the lighter particles will be higher than the heavier particles. That is, the lighter particles will leave the container faster than the heavier particles. Over time, the vapor pressure of the greater number of heavier particles will be higher than the vapor pressure of the lighter particles.
=> VP as function of time => VP(Ar) > VP(Ne) > VP(He).
Review Graham's Law => Effusion Rate ∝ 1/√formula mass.
Si -Atomic number -14 -1s2 2s2 2p6 3s2 3p2 - 4 valence electrons
