A 20.0 % by mass solution of phosphoric acid (H3PO4) in water has a density of 1.114 g/mL at 20°C. What is the molarity of this
2 answers:
Answer:
Molarity is 2.272M
Explanation:
The mass % of phosphoric acid is 20.0%
It means in 100 g of solution there is 20g of phosphoric acid in it.
Molarity = moles of solute dissolved per litre of solution.
So we need volume of solution
Volume can be calculated from mass and density as
Volume = mass / Density = 100/1.114 = 89.77 mL = 0.08977 L
Moles of solute = mass of solute / molar mass of solute
moles of solute = 20g / 98 = 0.204
molarity =
You might be interested in
Answer:
Explanation:
Step 1. Identify the Group that contains X
We look at the consecutive ionization energies and hunt for a big jump between them
We see a big jump between n = 2 and n = 3. This indicates that X has two valence electrons.
We can easily remove two electrons, but the third electron requires much more energy. That electron must be in the stable, filled, inner core.
So, X is in Group 2 and P is in Group 15.
Step 2. Identify the Compound
X can lose two valence electrons to reach a stable octet, and P can do the same by gaining three electrons.
We must have 3 X atoms for every 2 P atoms.
The formula of the compound is .