Answer:
a) Decreasing the pH
Explanation:
What we need to know to solve this problem is that we have an equilibrium for the dissolution of Mg(OH)₂ and we are bringing changes and need to know which one will increase the solubility of this hydroxide.
From LeChateliers principle we know that after any change brought to the equilibrium, the system will react in such a way as to restore the equilibrium by minimizing the disturbance.
Lets see now how our equilibrium will react for the given changes:
a) Decreasing pH
Decreasing pH effectively means we are adding acid to the equilibrium. This acid will consume part of the hydroxide ion, and the system will then shift to to the production of some hydroxide to restore equilibrium.
Therefore Mg(OH)₂ will become more soluble.
b) Increasing the pH
Increasing the pH will have the opposite effect as in part A, and will shift the equilibrium to the reactant side precipitating some Mg(OH)₂
c) Adding NH₃
NH₃ is a weak base therefore it will produce some hydroxide ion governed by the equilibrium
NH₃ + H₂O ⇆ NH₄⁺ + OH⁻
Therefore the equilibrium will shift in the same manner as in part b), that is precipitating some Mg(OH)₂.
d) Addig Mg(NO₃)₂
Here we will be adding Mg²⁺ to the equilibrium, and the system will react to remove some of the added Mg²⁺ making the Mg(OH)₂ less soluble.
Answer:
n = 7.86 mol
Explanation:
This question can be solved using the ideal gas law of PV = nRT.
Temperature must be in K, so we will convert 22.5C to 295 K ( Kelvin = C + 273).
R is the ideal gas constant of 0.0821.
(2.24atm)(85.0L) = n(0.0821)(295K)
Isolate n to get:
n = (2.24atm)(85.0L)/(0.0821)(295K)
n = 7.86 mol
Answer:
methanol because it is liquid at room temperature which means that it melts at a lower temperature
Answer:
d. directly proportional to the number of moles of the gas.
Explanation:
The formula for the partial pressure of a gas is written as -
P = n * P ( total )
P = partial pressure of the gas ,
n = mole fraction of the gas ,
P ( total ) = Total pressure of the mixture of gas .
Hence , from the above equation ,
the partial pressure is directly proportional to the mole fraction , i.e. , on increasing the number of moles of gas , the partial pressure increases .
Balanced chemical reaction: 2CH₄(g) ⇄ C₂H₂(g) + 3H₂(g).
1) In a chemical reaction, chemical equilibrium is the state in which both reactants (methane CH₄) and products (ethyne C₂H₂ and hydrogen H₂) are present in concentrations which have no further tendency to change with time.
2) At equilibrium, both the forward and reverse reactions are still occurring.
3) Reaction rates of the forward and backward reactions are equal and there are no changes in the concentrations of the reactants and products.