Answer:
0.032 L of NaOH
Explanation:
The reaction is;
Cr^3+(aq) + 3OH^- (aq) -----> Cr(OH)3(s)
Amount of Cr^3+ = 0.550 × 0.0250 = 0.01375 moles
If 1 mole of Cr^3+ reacts with 3 moles of OH^-
0.01375 moles of Cr^3+ reacts with 0.01375 moles × 3/1
= 0.04125 moles of OH^-
Hence we need 0.04125 moles/1.27 M = 0.032 L of NaOH