Answer:
The correct answer is 146 g/mol
Explanation:
<em>Freezing point depression</em> is a colligative property related to the number of particles of solute dissolved in a solvent. It is given by:
ΔTf = Kf x m
Where ΔTf is the freezing point depression (in ºC), Kf is a constant for the solvent and m is the molality of solution. From the problem, we know the following data:
ΔTf = 1.02ºC
Kf = 5.12ºC/m
From this, we can calculate the molality:
m = ΔTf/Kf = 1.02ºC/(5.12ºC/m)= 0.199 m
The molality of a solution is defined as the moles of solute per kg of solvent. Thus, we can multiply the molality by the mass of solvent in kg (250 g= 0.25 kg) to obtain the moles of solute:
0.199 mol/kg benzene x 0.25 kg = 0.0498 moles solute
There are 0.0498 moles of solute dissolved in the solution. To calculate the molar mass of the solute, we divide the mass (7.27 g) into the moles:
molar mass = mass/mol = 7.27 g/(0.0498 mol) = 145.9 g/mol ≅ 146 g/mol
<em>Therefore, the molar mass of the compound is 146 g/mol </em>
Answer:
Explanation:
Your unbalanced nuclear equation is:
The main point to remember in balancing nuclear equations is that the sums of the superscripts and the subscripts must be the same on each side of the equation.
Then
84 = x + 2, so x = 84 - 2 = 82
210 = y + 4, so y = 210 - 4 = 206
Element 82 is lead, so the nuclear equation becomes
Answer:
1 and 2
Trigonal planar
Tetrahedral
Trigonal Planar
Linear
Bent ( v- shape)
Explanation:
The highlighted atoms has a delocalized lone pair - 1 and 2
All sp2-hybridized carbon atoms have geometry- Trigonal planar
All sp3-hybridized carbon atoms have geometry - Tetrahedral
The nitrogen atom has geometry - Trigonal Planar
The oxygen atom of the C=O bond has geometry - Linear
and the other oxygen atom has geometry - Bent ( v- shape)
P.S - The correct question is -
The answer is 6.88.
Solution:
We can calculate for the percent composition of CaCl2 by mass by dividing the mass of the CaCl2 solute by the mass of the solution and then multiply by 100. The total mass of the resulting solution is the sum of the mass of CaCl2 solute and the mass of water solvent. Therefore, the percent composition of CaCl2 by mass is
% by mass = (mass of the solute / mass of the solution)*100
= mass of solute / (mass of the solute + mass of the solvent)*100
= (27.7 g CaCl2 / 27.7g + 375g) * 100
= 6.88
Answer:
count how many electrons it 'owns'
