Answer:
The correct answer is 2.016 x 10⁻¹⁷
Explanation:
We have the following chemical reactions and their equilibrium constants (K):
(1) H₂CO₃(aq) + H₂O ⇒ H₃O⁺(aq) + HCO₃⁻(aq) K₁= 4.20×10⁻⁷
(2) HCO₃⁻(aq) + H₂O ⇒ H₃O⁺(aq) + CO₃²⁻(aq) K₂= 4.80×10⁻¹¹
And we have to obtain K for the following reaction:
H₂CO₃(aq) + 2H₂O ⇒ 2H₃O⁺(aq) + CO₃²⁻(aq)
If we add equations (1) and (2) we obtain the the desired equation. Remember that when we add chemical equations, the global equilibrium constant is the product of the constants.
H₂CO₃(aq) + H₂O ⇒ H₃O⁺(aq) + <em><u>HCO₃⁻(aq)</u></em> K₁= 4.20×10⁻⁷
+
<em><u>HCO₃⁻(aq)</u></em> + H₂O ⇒ H₃O⁺(aq) + CO₃²⁻(aq) K₂= 4.80×10⁻¹¹
-------------------------------------------------------------
H₂CO₃(aq) + 2H₂O ⇒ 2H₃O⁺(aq) + CO₃²⁻(aq) K= K₁ x K₂
K = K₁ x K₂ = (4.20×10⁻⁷) x (4.80×10⁻¹¹) = 2.016 x 10⁻¹⁷
Answer:
B
Explanation:
A. Wrong
The volume of water in 2kg of water might not be 2L
D is correct.
Firstly, we need to know that the number of moles equals the mass over the molar mass. Doing this with the particular data in tie question would give 0.2M.
Hence it is essential that what we get is 0.2M in one liter. But since we are gunning for 2L, adding more than one liter of water would affect the molarity, that is why it now will be 0.1M in 2L
C is wrong
What is prepared here is 0.05M in 2L
B is wrong
What is needed is actually 2L of water and not the total volume of both being 2L
E is wrong
Hey there!
Elements and compounds are purely homogeneous substances and they have a constant composition throughout. Elements and compounds cannot be separated into their respective constituents by physical means. Compounds and mixtures are made up of different elements or different atoms.
