Asolution with a volume of 1.00 l is 0.450 m in ch 3 cooh(aq) and 0.550 m in ch 3 coona(aq). what will the ph be after 0.0800 mol of hcl is added to the solution?

Before addition of HCl,

conc. of CH3COOH = 0.450 M
conc. of CH3COONa = 0.550 M

After addition of 0.08 M HCl, following reaction occurs in system:
HCl + CH3COONa ↔  CH3COOH + NaCl

Thus, in reaction system conc. of CH3COOH will increase to 0.53 M (0.08M + 0.450M)
And, conc to CH3COONa will reduce to 0.47 M (0.550M - 0.08M)

Now, conc. of H+ ions = ka
where ka = dissociation constant for acid = 10^-5 for Ch3COOH

∴ conc. of H+ ions = 
                              = 1.1277 x 10^-5

Now, pH = -log [H+] = -log (1.1227 x 10^-5) = 4.94

The answer options is d

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer