Water: hydrogen bonding
carbon tetrafluoride: dispersion or Van del Waals
dichloromethane: dipole-dipole
<u>Answer:</u> The correct option is A) a nitrogen molecule.
<u>Explanation:</u>
Polar covalent molecules are defined as chemical compounds in which the difference in electronegativity between the atoms is not equal to 0. These molecules are formed by heteronuclear molecules.
Heteronuclear molecules are defined as the molecules which are formed by the combination of more than one type of atom having a different nucleus.
Non-polar covalent molecules are defined as chemical compounds in which the difference in electronegativity between the atoms is equal to 0. These molecules are formed by homonuclear molecules.
Homonuclear molecules are defined as the molecules which are formed by the combination of one type of atom having the same nucleus.
From the given options:
It is a homonuclear molecule formed by the combination of 2 nitrogen atoms
- B) A nitrogen monoxide molecule
It is a heteronuclear molecule formed by the combination of 1 nitrogen and 1 oxygen atoms
- C) A linear nitrogen oxide molecule with nitrogen in the center
It is a heteronuclear molecule formed by the combination of 2 nitrogen and 1 oxygen atom and has some dipole moment. Thus, is considered a polar molecule
- D) A bent nitrogen dioxide molecule with nitrogen in the center
It is a heteronuclear molecule formed by the combination of 1 nitrogen and 2 oxygen atoms and has some dipole moment. Thus, is considered a polar molecule
Hence, the correct option is A) a nitrogen molecule.
18. <span>Answer is </span>
A<span>
<span>Since the enthalpy of reaction is positive, the
forward reaction is<span> an endothermic reaction which means the energy
is gained from the surrounding to happen the reaction. If the temperature
decreases, according to the </span></span>Le Chatelier's principle, the system tries to become equilibrium
by increasing temperature. Since forward reaction is endothermic (because of
the bond breaking), the backward reaction is exothermic (because of the bond
making) which releases the energy to the surroundings. This makes the increase
of temperature. So if the backward reaction is promoted because of the decrease
of temperature, then the concentration of H</span><span>₂ will decrease.</span>
<span>
</span>
19. Answer is A.
The reactant side
has 2 moles/molecules of reactants and the product side has 4 moles/molecules
of products which come from 1 N₂(g) and 3 H₂<span>(g). If the pressure is reduced in the system, according to the Le Chatelier's principle, the
system tries to increase the pressure. </span><span>Hence, forward
reaction is promoted because of the higher number
of molecules in product side. If the forward reaction is promoted, the
concentration of NH</span>₃(g) will decreased.
<span>20. </span>Answer is C.
If the concentration
of reactant is increased in the
system, according to the Le Chatelier's principle, the system tries
to reduce the concentration of that reactant. So if NH₃(g) concentration
is increased, then to be equilibrium, the forward reaction will be promoted.
Then the concentration of N₂<span>(g) will increase.</span>
<span> </span>
The reaction is not balanced
<h3>Further explanation</h3>
Given
Reaction
2Fe(s)+3O₂(g)⇒2Fe₂O₃(s)
Required
The number of atoms
Solution
In a balanced chemical equation, the number of atoms in the compound that reacts (the reactants and products) will have the same number
Reactants : Fe(s)+O₂(g)
Fe = 2 atoms
O = 3 x 2 = 6 atoms
Products : Fe₂O₃(s)
Fe = 2 x 2 = 4 atoms
O = 2 x 3 = 6 atoms
The reaction is not balanced because the number of Fe atoms is not the same
The balanced reaction should be:
4Fe(s)+3O₂(g)⇒2Fe₂O₃(s)
Answer:
The volume of the gas will be 78.31 L at 1.7 °C.
Explanation:
We can find the temperature of the gas by the ideal gas law equation:
Where:
n: is the number of moles
V: is the volume
T: is the temperature
R: is the gas constant = 0.082 L*atm/(K*mol)
From the initial we can find the number of moles:
Now, we can find the temperature with the final conditions:
The temperature in Celsius is:
Therefore, the volume of the gas will be 78.31 L at 1.7 °C.
I hope it helps you!