5.If 30mL of 0.5M NaOH(aq) was used to neutralize 10mL of HCl(aq), what is the concentration of the acid? Show work.

0.15M

Explanation:

NaOH + HCl -->NaCl + H2O

moles of NaOH reacted with HCl

(0.5 × 30)/1000 = 1.5 × 10^ -3

so the moles of HCl reacted with NaOH

1.5 × 10^ -3

concentration of HCl = ( 1.5 × 10^ -3)/10 ×1000

c.

explanation:

it's c. elements are placed in rows based on how may valencies electrons have.