The correct option is B 2.35
pHsolution1=2 ; C1=[H+]=10−2pOHsolution2=3 ; C2=[OH−]=10−3Cf=[H+]remains after neutralization V1=500 mL , V2=500 mLVf=V1+V2=1000 mLApplying:
C1V1−C2V2=CfVfCf=C1V1−C2V2Vf=(10−2× 500)−(10−3× 500)1000 =4.5×10−3pH=− log10[4.5×10−3]pH=3−0.65=2.35