Acetic acid is the closest to 4.5 in my opinion.
Answer:
a) Xbenzene = 0.283
b) Xtoluene = 0.717
Explanation:
At T = 20°C:
⇒ vapor pressure of benzene (P*b) = 75 torr
⇒ vapor pressure toluene (P*t) = 22 torr
Raoult's law:
∴ Pi: partial pressure of i
∴ Xi: mole fraction
∴ P*i: vapor pressure at T
a) solution: benzene (b) + toluene (t)
∴ Psln = 37 torr; at T=20°C
⇒ Psln = Pb + Pt
∴ Pb = (Xb)*(P*b)
∴ Pt = (Xt)*(P*t)
∴ Xb + Xt = 1
⇒ Psln = 37 torr = (Xb)(75 torr) + (1 - Xb)(22 torr)
⇒ 37 torr - 22 torr = (75 torr)Xb - (22 torr)Xb
⇒ 15 torr = 53 torrXb
⇒ Xb = 15 torr / 53 torr
⇒ Xb = 0.283
b) Xb + Xt = 1
⇒ Xt = 1 - Xb
⇒ Xt = 1 - 0.283
⇒ Xt = 0.717
Answer:
The diluted solution is 0.65 M
Explanation:
Dilution formula to solve the problem is:
M concentrated . V concentrated = M Diluted . V diluted
We can also make a rule of three though.
In 1000 mL of concentrated solution, we have 13.1 moles of HNO₃
So in 25 mL we have (25 . 13.1 ) / 1000 = 0.327 moles of HNO₃
This moles are also in 0.500 L of diluted solution, the new molarity will be:
0.327 mol / 0.5L = 0.65 M
Molarity of diluted solution must be always lower than concentrated solution, otherwise the excersise is wrong.
If we replace in the formula
13.1 M . 25 mL = 500 mL . M diluted
M diluted = 13.1 m . 25 mL / 500 mL = 0.65 M
Answer:
D
Explanation:
According to the law of conservation of mass, matter can neither be created nor destroyed. The implication of this is that the total mass of reactants should be equal to the total mass of products.
There should be equal masses of reactants and products on both sides of the reaction equation. This most important condition is only satisfied by option D.
