Answer:
Choice B. The solid with hydrogen bonding.
Assumption: the molecules in the four choices are of similar sizes.
Explanation:
Molecules in a molecular solid are held intact with intermolecular forces. To melt the solid, it is necessary to overcome these forces. The stronger the intermolecular forces, the more energy will be required to overcome these attractions and melt the solid. That corresponds to a high melting point.
For molecules of similar sizes,
- The strength of hydrogen bonding will be stronger than the strength of dipole-dipole attractions.
- The strength of dipole-dipole attractions (also known as permanent dipole) will be stronger than the strength of the induced dipole attractions (also known as London Dispersion Forces.)
That is:
Strength of Hydrogen bond > Strength of Dipole-dipole attractions > Strength of Induced dipole attractions.
Accordingly,
Melting point due to Hydrogen bond > Melting point due to Dipole-dipole attractions > Melting point due to Induced Dipole attractions.
- Induced dipole is possible between all molecules.
- Dipole-dipole force is possible only between polar molecules.
- Hydrogen bonds are possible only in molecules that contain
atoms that are bonded directly to atoms of
,
, or
.
As a result, induced dipoles are the only force possible between molecules of the solid in choice C. Assume that the molecules are of similar sizes, such that the strengths of induced dipole are similar for these molecules.
Melting point in choice B > Melting point in choice D > Melting point in choice A and C.
Answer:
8.45 M
Explanation:
To solve this problem we need to keep in mind the <em>definition of molarity</em>:
- Molarity = moles / volume
First we<u> calculate the moles of AlCl₃ </u>in 0.672 L of a 4.78 M solution:
- Moles = Molarity * volume
Then we <u>calculate the new molarity of the AlCl₃ solution</u> using that <em>number of moles, which remains the same throughout the evaporation process</em>:
- New Molarity = 3.212 moles / 0.380 L
When a mixture of 10 moles of SO2 and 15 moles of O2 was passed over a catalyst, 10 moles of SO3 was formed.
Answer:
The final volume will be 24.7 cm³
Explanation:
<u>Step 1:</u> Data given:
Initial temperature = 180 °C
initial volume = 13 cm³ = 13 mL
The mixture is heated to a fina,l temperature of 587 °C
Pressure and amount = constant
<u>Step 2: </u>Calculate final volume
V1/T1 = V2/T2
with V1 = the initial volume V1 = 13 mL = 13*10^-3
with T1 = the initial temperature = 180 °C = 453 Kelvin
with V2 = the final volume = TO BE DETERMINED
with T2 = the final temperature = 587 °C = 860 Kelvin
V2 = (V1*T2)/T1
V2 = (13 mL *860 Kelvin) /453 Kelvin
V2 = 24.68 mL = 24.7 cm³
The final volume will be 24.7 cm³
The number of atoms : N = 2.709 x 10⁴⁶
<h3>Further explanation</h3>
Given
4.5 x 10²² moles of CO₂
Required
The number of atoms
Solution
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
Input the value :
N = 4.5 x 10²² x 6.02 x 10²³
N = 2.709 x 10⁴⁶