A student uses 57.4 ml of 0.2m of RbOH to titrate 25.0ml of HcLo3. What is the concentration of HcLo3?
You really to get a handle on the caps key. Also you need to be reminded that 20.2m and 0.2M are not the same thing. I assume you meant 0.2M.
mLbase x M base = mL acid x M acid