To find the hydrogen ions concentrations, we use the following formula.
![\lbrack H^+\rbrack=10^(-pH)](https://img.qammunity.org/2023/formulas/chemistry/college/3lrjv5qnwzunk9ej1g2icka8rnqbbecpof.png)
(a) When pH = 2.42, we obtain the following.
![\lbrack H^+\rbrack=10^(-2.42)\approx^{}3.8*10^(-3)M](https://img.qammunity.org/2023/formulas/chemistry/college/hwe4gfew3ysj713xtt6sygzztea11taz1z.png)
(b) When pH = 11.21.
![\lbrack H^+\rbrack=10^(-11.21)\approx6.2*10^(-12)M](https://img.qammunity.org/2023/formulas/chemistry/college/xqsvi92e04ulyy12v75m1rhhhy4bkng920.png)
(c) When pH = 6.96.
![\lbrack H^+\rbrack=10^(-6.96)=1.1*10^(-7)M](https://img.qammunity.org/2023/formulas/chemistry/college/yvaa81hc2yhkn31d2jad02zrm4k4i297t4.png)
(d) When pH = 15.00.
![\lbrack H^+\rbrack=10^(-15.00)=1*10^(-15)M](https://img.qammunity.org/2023/formulas/chemistry/college/invz7ljrgrgcdvc0kt87fez11fegwdaki3.png)
Therefore, the hydrogen ion concentration for each case is
• 3.8x10^-3 M.
,
• 6.2x10^-12 M.
,
• 1.1x10^-7 M.
,
• 1x10^-15 M.