C. Cello playing music at a concert
Answer:
pH = 2.69
Explanation:
The complete question is:<em> An analytical chemist is titrating 182.2 mL of a 1.200 M solution of nitrous acid (HNO2) with a solution of 0.8400 M KOH. The pKa of nitrous acid is 3.35. Calculate the pH of the acid solution after the chemist has added 46.44 mL of the KOH solution to it.</em>
<em />
The reaction of HNO₂ with KOH is:
HNO₂ + KOH → NO₂⁻ + H₂O + K⁺
Moles of HNO₂ and KOH that react are:
HNO₂ = 0.1822L × (1.200mol / L) = <em>0.21864 moles HNO₂</em>
KOH = 0.04644L × (0.8400mol / L) = <em>0.0390 moles KOH</em>
That means after the reaction, moles of HNO₂ and NO₂⁻ after the reaction are:
NO₂⁻ = 0.03900 moles KOH = moles NO₂⁻
HNO₂ = 0.21864 moles HNO₂ - 0.03900 moles = 0.17964 moles HNO₂
It is possible to find the pH of this buffer (<em>Mixture of a weak acid, HNO₂ with the conjugate base, NO₂⁻), </em>using H-H equation for this system:
pH = pKa + log₁₀ [NO₂⁻] / [HNO₂]
pH = 3.35 + log₁₀ [0.03900mol] / [0.17964mol]
<h3>pH = 2.69</h3>
Answer:
Enriched uranium-
Explanation:
Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written ²³⁵U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (²³⁸U with 99.2739–99.2752% natural abundance), uranium-235 (²³⁵U, 0.7198–0.7202%), and uranium-234 (²³⁴U, 0.0050–0.0059%). U is the only nuclide existing in nature (in any appreciable amount) that is fissile with thermal neutrons.
<span>refrigerant
The refrigerant does all the work. It's a strategy in which a little measure of fluorescent color is infused into and circled through a working framework of an A/C The refrigerant blend will escape and gather at all break destinations.</span>
