Flourine
Chlorine
Bromine
Iodine
Astatine
Answer:
pH = 12.8
Explanation:
HF + NaOH → F⁻ + Na⁺ + H₂O
<em>1 mole of HF reacts with 1 mole of NaOH</em>
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Initial moles of HF and NaOH are:
HF = 0.018L × (0.308mol / L) = 5.544x10⁻³mol HF
NaOH = 0.023L × (0.361mol / L) = 8.303x10⁻³mol NaOH
That means moles of NaOH remains after reaction are:
8.303x10⁻³mol - 5.544x10⁻³mol = <em>2.759x10⁻³moles NaOH</em>
Total volume is 18.0mL + 23.0mL = 41.0mL = 0.0410L
Molar concentration of NaOH is
2.759x10⁻³moles NaOH / 0.0410L = 0.0673M = [OH⁻]
pOH = - log [OH⁻] = 1.17
As pH = 14 - pOH
<em>pH = 12.8</em>
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In the past, restaurants had four hours, straight through, to cool food to 41°F or lower. Now the FDA recommends cooling food in two stages -- from 135°F to 70°F in two hours then from 70°F to 41°F or lower in an additional four hours for a total cooling time of six hours
Explanation:
the two-stage cooling method<span> is a </span><span>Food Code </span>counselled<span> procedure for cooling food in restaurants and foodservice </span>institutions<span>. </span>within the<span> two-stage cooling </span>methodology<span>, food is</span><span> cooled from 140° F (60° C) to 70° F (21° C) </span>among 2<span> hours and to 41° F (5° C) or lower </span>among<span> four hours. Use of this cooling </span>methodology<span> ensures that food is cooled quickly and safely and has no harmful effects.</span>
Answer:
Hiya there!
Explanation:
A covalent bond forms when the difference between the electronegativities of two atoms is too small for an electron transfer to occur to form ions. Shared electrons located in the space between the two nuclei are called bonding electrons. The bonded pair is the “glue” that holds the atoms together in molecular units.
<em><u>Hope this helped!</u></em> ^w^
Credit sourced from "sciencedirect.com"
