C₁ * V₁ = C₂ * V₂
18 * V₁ = 6.0 * 250
18 V₁ = 1500
V₁ = 1500 / 18
V₁ = 83.33 mL
hope this helps!
Stratus clouds reside below the 6,000ft range.
Altocumulus clouds reside in the 6,500-20,000ft range.
Cirrus clouds reside above the 20,000ft range.
Ordered from highest to lowest, the sequence of clouds will be:
Cirrus
Altocumulus
Stratus
What is reflux? isn't it like when u aren't able to digest something?
Ultrasound is sound or vibrations, having an ultrasonic frequency, particularly as used in medical imaging. Ultrasound is more commonly used in medical terminology than in industry. Infrasound is sound waves with frequencies below the lower limit of human audibility.
Answer:
11.31g NaClO₂
Explanation:
<em> Is given 250mL of a 1.60M chlorous acid HClO2 solution. Ka is 1.110x10⁻². What mass of NaClO₂ should the student dissolve in the HClO2 solution to turn it into a buffer with pH =1.45? </em>
It is possible to answer this question using Henderson-Hasselbalch equation:
pH = pKa + log₁₀ [A⁻] / [HA]
<em>Where pKa is -log Ka = 1.9547; [A⁻] is the concentration of the conjugate base (NaClO₂), [HA] the concentration of the weak acid</em>
You can change the concentration of the substance if you write the moles of the substances:
[Moles HClO₂] = 250mL = 0.25L×(1.60mol /L) = <em>0.40 moles HClO₂</em>
Replacing in H-H expression, as the pH you want is 1.45:
1.45 = 1.9547 + log₁₀ [Moles NaClO₂] / [0.40 moles HClO₂]
-0.5047 = log₁₀ [Moles NaClO₂] / [0.40 moles HClO₂]
<em>0.3128 = </em>[Moles NaClO₂] / [0.40 moles HClO₂]
0.1251 = Moles NaClO₂
As molar mass of NaClO₂ is 90.44g/mol, mass of 0.1251 moles of NaClO₂ is:
0.1251 moles NaClO₂ ₓ (90.44g / mol) =
<h3>11.31g NaClO₂</h3>