Question

Seawater has a pH of 8.10. What is its hydrogen-ion concentration? 

A. 1.0 x 10^–8 M. 

B. 8.0 x 10^–1 M. 

C. 7.9 x 10^–9 M. 

D. 1.3 x 10^–6 M. 

E. 5.9 M

Answer 1

Correct option  (C) 7.9 x 10^–9 M. 

Explanation:

In order to solve for the hydrogen-ion concentration, solve 10^–8.10. Without a calculator, you may again notice that Responses B, D, and E are not correct. It should also be reasonable that 10^–8, as in Response A, is not equal to 10^–8.10. Therefore, the correct answer must be Response C.