According to Raoult's low:
We will use this formula: Vp(Solution) = mole fraction of solvent * Vp(solvent)
∴ mole fraction of solvent = Vp(Solu) / Vp (Solv)
when we have Vp(solu) = 25.7 torr & Vp(solv) = 31.8 torr
So by substitution:
∴ mole fraction of solvent = 25.7 / 31.8 =0.808
when we assume the moles of solute NaCl = X
and according to the mole fraction of solvent formula:
mole fraction of solvent = moles of solvent / (moles of solvent + moles of solute)
by substitute:
∴ 0.808 = 0.115 / (0.115 + X)
So X (the no.of moles of NaCl) = 0.027 m
Answer:
2.33g of iron (iii) chloride
50.0 mL of 5.00 M of sodium phosphate
FeCl3 + Na3PO4 > Fe(PO4) + 3NaCl
mol = conc × vol = 0.5 × 50/1000 = 0.025 mol Na3PO4
from the equation:
1 mol of Na3PO4 reacts with 1 mol FeCl3 = 3 mol of NaCl
0.025 mol = x
x = 0.0025 × 3 = 0.075 mol NaCl
mass = 0.075 g × 59 g/mol = 4.425 g NaCl
i guessed all of this so i dont know i it is correct
In this question given concerning the atom's electron, the number of energy sublevels present in the principal energy level n = 4 is to be determined. For this matter, it should be remembered that the number of sublevels of a certain principal energy level is equal to n. For this item, the number of sublevels is also 4. That is s, p, d and f.
The correct answer is B. Chewing in the mouth breaks food into small pieces.
Explanation:
In physical changes, substances do not change their chemical composition or properties but only physical features such as this. This occurs during the chewing because the action of chewing only makes food to be broken down in smaller pieces but does not change its identity, composition, or properties. This does not occur once the food is in contact with saliva, the acid in the stomach, etc. because in these cases, the food reacts with other substances and a chemical reaction occurs, which changes food's identity and composition.
