Answer:
Mole fraction of Nacl is 0.173
Explanation:
we know that
where,
P
sol - the vapor pressure of the solution
χ solvent - the mole fraction of the solvent
P
∘
solvent - the vapor pressure of the pure solvent
This means that in order to be able to calculate the mole fraction of sodium chloride, you need to know what the vapor pressure of pure water is at
25
°
C You can use an online calculator to find that the vapor pressure of pure water at 25 C is equal to about 23.8 torr
.
=0.827
Also we know that
This means that the mole fraction of sodium chloride is
χ_{Nacl}= 1-Χ_{water}
= 1-0.827 =0.173
13
Al
Aluminum
Atomic mass 26.982
Answer:
35 . 29%
Explanation:
no. of questions in test =34
no. of questions answered correctly =22
therefore, no. of questions answered incorrectly =34 - 22
=12
error percentage = 12/34 * 100
=35 .29 %
Answer:
The number of formula units in 3.81 g of potassium chloride (KCl) is approximately 3.08 × 10²²
Explanation:
The given parameters is as follows;
The mass of potassium chloride produced in the chemical reaction (KCl) = 3.81 g
The required information = The number of formula units of potassium chloride (KCl)
The Molar Mass of KCl = 74.5513 g/mol
Therefore, we have;
1 mole of a substance, contains Avogadro's number (6.022 × 10²³) of formula units
Therefore;
0.051106 moles of KCl contains 0.051106 × 6.022 × 10²³ ≈ 3.077588 × 10²² formula units
From which we have, the number of formula units in 3.81 g of potassium chloride (KCl) ≈ 3.08 × 10²² formula units.
Answer:
C. 1.3 mol
Explanation:
PV = nRT
where P is absolute pressure,
V is volume,
n is number of moles,
R is universal gas constant,
and T is absolute temperature.
Given:
P = 121.59 kPa
V = 31 L
T = 360 K
R = 8.3145 L kPa / mol / K
Find: n
n = PV / (RT)
n = (121.59 kPa × 31 L) / (8.3145 L kPa / mol / K × 360 K)
n = (3769.29 L kPa) / (2993.22 L kPa / mol)
n = 1.26 mol
Round to two significant figures, there are 1.3 moles of gas.
