[ 483 ] Physical Science GED ® TEST SCIENCE FLASH REVIEW • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • pH H + (moles per liter) H + (moles per liter) Acidic 0 10 0 1.0 1 2 10 –2 0.01 3 4 10 –4 0.0001 5 6 10 –6 0.000001 Neutral 7 8 10 –8 0.00000001 9 10 10 –10 0.0000000001 11 12 10 –12 0.000000000001 13 Basic 14 10 –14 0.00000000000001 Based on the information in the table, which of these solutions has the greatest concentration of hydrogen ions? A. pH 2.5 B. pH 4.0 C. pH 7.5 D. pH 10.5