Answer:
0.0369M of V³⁺
Explanation:
The moles of EDTA added to the solution containing V³⁺ are:
0.025L ₓ (0.0630mol / L) = 0.001575 moles of EDTA.
The excess of EDTA was titrated with Ga³⁺. Moles required of Ga³⁺ = Moles in excess of EDTA are:
0.013L ₓ (0.0360mol / L) = 0.000468 moles.
That means initial moles of EDTA that react with V³⁺ solution are:
0.001575 moles - 0.000468 moles = 0.001107 moles of EDTA = moles of V³⁺
As volume of the solution was 30.0mL = 0.0300L, the concentration of the solution of V³⁺ is:
0.001107 moles V³⁺ / 0.0300L = <em>0.0369M of V³⁺</em>
Answer:
Kb = 1.6 × 10⁻⁵
Explanation:
Step 1: Given data
Acid dissociation constant of hydrocyanic acid (Ka): 6.2 × 10⁻¹⁰
Concentration of cyanide ion (Cb): 0.1 M
Step 2: Calculate the basic dissociation constant (Kb) of cyanide ion
We have the Ka of HCN. We can calculate the Kb of its conjugate base using the following expression.
Ka × Kb = Kw = 1.0 × 10⁻¹⁴
Kb = 1.0 × 10⁻¹⁴/Ka
Kb = 1.0 × 10⁻¹⁴/6.2 × 10⁻¹⁰
Kb = 1.6 × 10⁻⁵
Answer:
It's probably claim 3
Explanation:
It's not claim 1 because the amount of energy from the sun can't change and claim 2 doesn't really make sense.
The average between the volume at the top of and the bottom of the meniscus
Answer: The sample that contains the greater number of molecules is water.
Explanation: To calculate the number of molecules, it is used the Avogadro's number ( 
particles/molecules). So, considering that the mass to water and carbon dioxide is 1g (it can be any other number), the relationship between moles and molar weight is:
To water: 
= 0.05 moles.
Therefore,
1 mol ---- molecules
0.05 moles ---- x
x = 
molecules of water.
To carbon dioxide: 
= 0.02 moles.
Therefore,
1 mol ---- molecules
0.02 moles ---- y
y = 
molecules of carbon dioxide.
