Answer:
(E) changing temperature
Explanation:
Consider the following reversible balanced reaction:
aA+bB⇋cC+dD
If we know the molar concentrations of each of the reaction species, we can find the value of Kc using the relationship:
Kc = ([C]^c * [D]^d) / ([A]^a * [B]^b)
where:
[C] and [D] are the concentrations of the products in the equilibrium; [A] and [B] reagent concentrations in equilibrium; already; b; c and d are the stoichiometric coefficients of the balanced equation. Concentrations are commonly expressed in molarity, which has units of moles / 1
There are some important things to remember when calculating Kc:
- <em>Kc is a constant for a specific reaction at a specific temperature</em>. If you change the reaction temperature, then Kc also changes
- Pure solids and liquids, including solvents, are not considered for equilibrium expression.
- The reaction must be balanced with the written coefficients as the minimum possible integer value in order to obtain the correct value of Kc
I believe the correct answer is C. The amount of catalyst is the same at the end as at the beginning of the reaction. Catalysts can't be consumed by the reaction thus is not D.
0.781 moles
Explanation:
We begin by balancing the chemical equation;
O₂ (g) + 2H₂ (g) → 2H₂O (g)
21.8 Liters = 21.8 Kgs
To find how many moles are in 28.1 Kg H₂O;
Molar mass of H₂O = 18 g/mol
28.1/18
= 1.56 moles
The mole ratio between water vapor and oxygen is;
1 : 2
x : 1.56
2x = 1.56
x = 1.56 / 2
x = 0.781
0.781 moles
The answer is A :) your welcome hope this helps
Here try this presentation, it should help :)
https://prezi.com/6ofdo3fadl9a/exothermic-and-endothermic-reactions-in-everyday-life/
