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 )
FALSE
Organisms may play only one role in an ecosystem. ... Each of the organisms in an ecosystem fills the energy role of producer, consumer, or decomposer.
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B.) Helium have <span>two protons and two electrons
Hope this helps!</span>
Answer:
λ = 0.45×10⁻⁶ m
Explanation:
Given data:
Wavelength of blue light = ?
Frequency of blue light = 6.69×10¹⁴ s⁻¹
Solution:
Formula;
Speed of wave = wavelength × frequency
Speed of wave = 3.00×10⁸ m/s
by putting vales,
3.00×10⁸ m/s = λ × 6.69×10¹⁴ s⁻¹
λ = 3.00×10⁸ m/s / 6.69×10¹⁴ s⁻¹
λ = 0.45×10⁻⁶ m
