Answer:
The answer is melting and freezing point.
Explanation:
That is not a question/problem and makes no sense whatsoever
Answer:
Kₐ = 6.7 x 10⁻⁴
Explanation:
First lets write the equilibrium expression, Ka , for the dissociation of hydrofluoric acid:
HF + H₂O ⇄ H₃O⁺ + F⁻
Kₐ = [ H₃O⁺ ] [ F⁻ ] /[ [ HF ]
Since we are given the pH we can calculate the [ H₃O⁺ ] ( pH = - log [ H₃O⁺ ] , and because the acid dissociates into a 1: 1 relation , we will also have [F⁻ ]. The [ HF ] is given in the question so we have all the information that is needed to compute Kₐ.
pH = -log [ H₃O⁺ ]
1.68 = - log [ H₃O⁺ ]
Taking antilog to both sides of this equation:
10^-1.68 = [ H₃O⁺ ] ⇒ 2.1 X 10⁻² M= [ H₃O⁺ ]
[ F⁻ ] = 2.1 X 10⁻² M
Solving for Kₐ :
Kₐ = ( 2.1 X 10⁻² ) x ( 2.1 X 10⁻² ) / 0.65 = 6.7 x 10⁻⁴
(Rounded to two significant figures, the powers of 10 have infinite precision )
Answer:
I would say the answer is b.
Explanation:
Answer:
3.2×10^-3 mol
Explanation:
The equation for molarity is M= n/L. Where "M" is Molarity, "n" is the number of moles of solute, and "L" is the total liters in solution.
The question gives you the volume in mL, so to convert "mL" to "L" you need to divide by 1000. (6.70mL/ 1000L)= 0.0067L.
Now you can plug the numbers into the equation. 0.480M= n/ 0.0067L), multiply (0.480M×0.0067L)= 0.003216 mol. The scientific notation is 3.2×10^-3, 10^-3 because you move the decimal back three times and 3.2 because there are 2 sig figs.