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>
Answer:
go look for that on google
Explanation:
The chemical formula for the compound containing 8.6 mol of sulfur and 3.42 mol of phosphorus is P₂S₅
<h3>How do I determine the formula of the compound?</h3>
From the question given above, the following data were obatined:
- Sulphur (S) = 8.6 moles
- Phosphorus (P) = 3.42 mole
- Chemical formula =?
The chemical formula of the compound can be obtained as follow:
Divide by their molar mass
S = 8.6 / 32 = 0.26875
P = 3.42 / 31 = 0.11032
Divide by the smallest
S = 0.26875 / 0.11032 = 2.44
P = 0.11032 / 0.11032 = 1
Multiply by 2 to express in whole number
S = 2.44 × 2 = 5
P = 1 × 2 = 2
Thus, the chemical formula is P₂S₅
Learn more about empirical formula:
brainly.com/question/9459553
#SPJ1
Always use this method !!! always
Answer:
B) Symmetrical and nonpolar
Step-by-step explanation:
The formula is H-C≡C-H.
Each C atom has <em>two</em> electron regions, so VSEPR theory predicts a <em>linear molecular geometry</em> (see image below).
The molecule is symmetrical, because the green line divides the molecule into two halves that are mirror images of each other.
The C-H bonds are slightly polar, because C is more electronegative than H (µ ≈ 0.4 D).
The C atoms are partially negative (red), while the H atoms are partially positive (blue).
However, the two C-H bond dipoles point in <em>opposite directions</em>, so they cancel each other. The molecule has <em>no net dipole moment.</em>
Acetylene is nonpolar.
