<h3>
Answer</h3>
HF
<h3>Explanation</h3>
A buffer solution contains <em>a weak acid</em> and<em> its conjugate base</em>. The two species shall have a similar concentration in the solution. It's also possible for <em>a weak base</em> and <em>its conjugate acid</em> to form a buffer solution.
The KF solution already contains large number of 
ions. The objective is to thus find its conjugate acid or base.
contains no proton 
and is unlikely to be a conjugate acid. Assuming that is a conjugate base. Adding one proton to would produce its conjugate acid.
Therefore 
is the conjugate acid of . happens to be a weak acid. As a result, combining with would produce a solution with large number of both the weak acid and its conjugate base, which is a buffer solution by definition.
Answer:
C
Explanation:
it has to have hydroniums
7.4x10^23 = molecules of silver nitrate sample
6.022x10^23 number of molecules per mole (Avogadro's number)
Divide molecules of AgNO3 by # of molecules per mol
7.4/6.022 = 1.229 mols AgNO3 (Sig Figs would put this at 1.3)
(I leave off the x10^23 because they both will divide out)
Use your periodic table to find the molar weight of silver nitrate.
107.868(Ag) + 14(N) + 3(16[O]) = 169.868g/mol AgNO3
Now multiply your moles of AgNO3 with your molar weight of AgNO3
1.229mol x 169.868g/mol = 208.767g AgNO3
Answer:
We will not know immediately
Explanation:
The distance of star Betelgeuse = 325 light years
Therefore, if it where to explode, at the location, we would have a supernovae such that the luminosity of the star multiplies several multiple times
However, due to the distance of Betelgeuse from the Earth, it will take the light of the explosion, 325 years to reach Earth and the explosion as it happens will not be noticed here on Earth immediately
