Question

What is the M of NaOH if it takes 40ml of NaOH to reach the equivalence point in a titration with 50ml of 0.2M HCL

Answer 1

NaOH+HCl ----->NaCl+H2O

number mole NaOH = number mole NaOH
M -molarity, V - volume
M(NaOH)*V(NaOH)  =  M(HCl)*V(HCl) 
M(NaOH)*40 ml  =  0.2 M*50 ml
M(NaOH)=0.2 M*50 ml/40 ml=1/4 M=0.25 M NaOH