Option d: copper.
Because copper is an element, not a mixture.
<span>Get a periodic table of elements. ...Find your element on the periodic table. ...Locate the element's atomic number. ...Determine the number of electrons. ...Look for the atomic mass of the element. ...<span>Subtract the atomic number from the atomic mass.</span></span>
pH of the buffer solution is 1.76.
Chemical dissociation of formic acid in the water:
HCOOH(aq) ⇄ HCOO⁻(aq) + H⁺(aq)
The solution of formic acid and formate ions is a buffer.
[HCOO⁻] = 0.015 M; equilibrium concentration of formate ions
[HCOOH] + [HCOO⁻] = 1.45 M; sum of concentration of formic acid and formate
[HCOOH] = 1.45 M - 0.015 M
[HCOOH] = 1.435 M; equilibrium concentration of formic acid
pKa = -logKa
pKa = -log 1.8×10⁻⁴ M
pKa = 3.74
Henderson–Hasselbalch equation: pH = pKa + log(cs/ck)
pH = 3.74 + log (0.015 M/1.435 M)
pH = 3.74 - 1.98
pH = 1.76
More about buffer: brainly.com/question/4177791
#SPJ4
Answer:
True
Explanation:
Water vapor is totally invisible.
Without it, there would be no clouds or rain or snow, since all of these require water vapor in order to form. All of the water vapor that evaporates from the surface of the Earth eventually returns as precipitation - rain or snow.
Helped by the <u><em>One</em></u> & <u><em>Only</em></u> <u><em>#QUEEN</em></u> aka <u><em>#DRIPPQUEENMO
</em></u>
<u><em>Hoped this helped! :)</em></u>