Answer:
Explanation:
A buffer is defined as an aqueous mixture of a weak acid and its conjugate base or vice versa.
In the systems:
H₂CO₃(aq) and KHCO₃(aq): Carbonic acid, H₂CO₃, is a weak acid that, in solution with its conjugate pair, HCO₃⁻ make a <em>buffer system.</em>
NaCl(aq) and NaOH(aq): NaCl is a salt and NaOH is a strong base. Thus, this system <em>is not </em> a buffer system.
H₂O(l) and HCl(aq): Water is a solvent and HCl a strong acid. This <em>is not </em>a buffer system.
HCl(aq) and NaOH(aq): HCl is a strong acid and NaOH a strong base. This <em>is not </em>a buffer system.
NaCl(aq) and NaNO₃(aq): Both NaCl and NaNO₃ are salts and this system <em>is not </em>a buffer system.
Reactivity trends of halogen:
1) Melting point and boiling points increased down the
group
2) Colour becomes darker.
E.g. Fluorine (pale yellow)
Chlorine (yellowish-green)
Bromine (reddish-brown)
Iodine (purplish-black)
Astatine (black)
3) The reactivity decreases down the group.
Reactivity:
F > Cl > Br > I > At
Answer:
5.64×10²³ atoms C
Explanation:
Convert moles of H to moles of C:
2.81 mol H × (2 mol C / 6 mol H) = 0.937 mol C
Convert moles of C to atoms of C:
0.937 mol C × (6.02×10²³ atoms C / mol C) = 5.64×10²³ atoms C
1,000 mL is the same as 10 dL.
