Answer:
Chromosphere
Explanation:
You see the middle layer of the sun’s atmosphere, the Chromosphere, at the start and end of a total eclipse.
Answer and explanation:
A chemical change occurs when new substances or materials are produced to have different chemical properties from the reactants.
Some examples of this are paper burning, fruit rotting, and metal rusting.
Answer:
1) [OH⁻] = 0.065 M
2) [H₃O⁺] = 1.54 x 10⁻¹³ M.
3) pH = 12.81.
Explanation:
HCl is completely dissociated yo its ions in solution:
<em>KOH + H₂O → H₃O⁺ + K⁺ + OH⁻,
</em>
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1) [OH⁻] = 0.065 M.
<em>2) [H₃O⁺]:
</em>
∵ [H₃O⁺][OH⁻] = 10⁻¹⁴.
∴ [H₃O⁺] = 10⁻¹⁴/[OH⁻] = 10⁻¹⁴/(0.065 M) = 1.54 x 10⁻¹³ M.
<em>3) pH:
</em>
For strong acids like HCl:
pH = - log[H₃O⁺] = - log[1.54 x 10⁻¹³ M] = 12.81.
Answer:
4.504g of acetic acid
Explanation:
The acetic acid in reaction with NaOH produce acetate ion, thus:
CH₃COOH + NaOH → CH₃COO⁻ + H₂O + Na⁺
<em>That means the moles of acetate buffer comes, in the first, from the acetic acid</em>
As you need 500mL (0,500L) of a 0.150M acetate buffer, moles are:
0.500L × (0.150mol / 1L) = <em>0.075 moles of acetate</em>. That is:
0.075mol = [CH₃COO⁻] + [CH₃COOH]
Thus, grams of acetic acid you need to prepare the buffer are:
0.075 moles acetic acid × (60.05g / 1mol) = <em>4.504g of acetic acid</em>
B. Both mechanical and chemical waethering
