Answer:
[HF]₀ = 0.125M
Explanation:
NaOH + HF => NaF + H₂O
Adding 20ml of 0.200M NaOH into 25ml of HF solution neutralizes 0.004 mole of HF leaving 0.004 mole NaF in 0.045L with 0.001M H⁺ at pH = 3. This is 0.089M NaF and 0.001M HF remaining.
=> 45ml of solution with pH = 3 and contains 0.089M NaF from titration becomes a common ion problem.
HF ⇄ H⁺ + F⁻
C(eq) [HF] 10⁻³M 0.089M (<= soln after adding 20ml 0.200M NaOH)
Ka = [H⁺][F⁻]/[HF]₀ => [HF]₀ = [H⁺][F⁻]/Ka
[HF]₀ = (0.001)(0.089)/(7.1 x 10⁻⁴) M = 0.125M
Answer:C
Explanation:you are seeing a lunar eclipse when the moon moves directly between the sun and the earth and casts a shadow. Hope this helps!
Answer:
Carbon
Explanation:
The non metal in the same group as Pb is carbon or C .
I hope this helps you.
The molarity of the stock Mn²⁺ ions is 0.0288 M
Based on the dilution formula;
- The molarity of A is 0.00144 M
- The molarity of B is 0.0000576 M
- The molarity of C is 0.000001152 M
<h3>What is the molarity of a solution?</h3>
The molarity of a solution is the number of moles of a solute dissolved in a given volume of solution in liters.
- Molarity = number of moles/volume
The molarity of the stock solution is:
moles of Mn²⁺ ions = mass / molar mass
molar mass of Mn²⁺ ions = 55.0 g/mol
moles of Mn²⁺ ions = 1.584 / 55
moles of Mn²⁺ ions = 0.0288 moles
molarity of Mn²⁺ ions = 0.0288 / 1
molarity of Mn²⁺ ions = 0.0288 M
The dilution formula is used to determine the molarities of A, B, and C.
C₁V₁ = C₂V₂
C₂ = C₁V₁ / V₂
Where;
- C₁ = initial molarity
- V₁ = initial volume
- C₂ = final molarity
- V₂ = final volume
Molarity of A = 50 * 0.0288 / 1000
Molarity of A = 0.00144 M
Molarity of B = 10 * 0.00144 / 250
Molarity of B = 0.0000576 M
Molarity of C = 10 * 0.0000576 / 500
Molarity of C = 0.000001152 M
Learn more about molarity at: brainly.com/question/17138838
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