Which of the following mixture has maximum ph?
a. 200 ml, m/10 h2s04 800 ml,m/10 naoh
b. 800 ml, m/10 hcl 200 ml, m/10 ba(oh)2
c. 500 ml, m/10 h2s04 500 ml, m/10 ba(oh)2
d. 250 ml, m/10 hno3 750 ml, m/10 koh