the term for a solution that has an equal concentration of h+ and oh- is
pH
Pure water is neutral . When an acid is dissolved in water , the pH will be less than 7 ( 25 ° C ) . When a base , or alkali , is dissolved in water , the pH will be greater than 7 . A solution of a strong acid , such as hydrochloric acid , at concentration 1 mol dm has a pH of 0 . A solution of a strong alkali , such as sodium hydroxide , at concentration 1 mol dm , has a pH of 14 . Thus , measured pH values will lie mostly in the range 0 to 14 , though negative pH values and values above 14 are entirely possible . Since pH is a logarithmic scale , a difference of one pH unit is equivalent to a tenfold difference in hydrogen ion concentration . The pH of neutrality is not exactly 7 ( 25 ° C ) , although this is a good approximation in most cases . Neutrality is defined as the condition where ( H ) = ( OH ) ( or the activities are equal ) . Since self - ionization of water holds the product of these concentration ( H ) × ( OH ) = K , it can be seen that at neutrality ( H ) = ( OH ) = √ ( K ) , or pH = pK / 2 . pK is approximately 14 but depends on ionic strength and temperature , and so the pH of neutrality does also . Pure water and a solution of NaCl in pure water are both neutral , since dissociation of water produces equal numbers of both ions . However the pH of the neutral NaCl solution will be slightly different from that of neutral pure water because the hydrogen and hydroxide ions ' activity is dependent on ionic strength , so K varies with ionic strength . 
Pure water is neutral . When an acid is dissolved in water , the pH will be less than 7 ( 25 ° C ) . When a base , or alkali , is dissolved in water , the pH will be greater than 7 . A solution of a strong acid , such as hydrochloric acid , at concentration 1 mol dm has a pH of 0 . A solution of a strong alkali , such as sodium hydroxide , at concentration 1 mol dm , has a pH of 14 . Thus , measured pH values will lie mostly in the range 0 to 14 , though negative pH values and values above 14 are entirely possible . Since pH is a logarithmic scale , a difference of one pH unit is equivalent to a tenfold difference in hydrogen ion concentration . The pH of neutrality is not exactly 7 ( 25 ° C ) , although this is a good approximation in most cases . Neutrality is defined as the condition where ( H ) = ( OH ) ( or the activities are equal ) . Since self - ionization of water holds the product of these concentration ( H ) × ( OH ) = K , it can be seen that at neutrality ( H ) = ( OH ) = √ ( K ) , or pH = pK / 2 . pK is approximately 14 but depends on ionic strength and temperature , and so the pH of neutrality does also . Pure water and a solution of NaCl in pure water are both neutral , since dissociation of water produces equal numbers of both ions . However the pH of the neutral NaCl solution will be slightly different from that of neutral pure water because the hydrogen and hydroxide ions ' activity is dependent on ionic strength , so K varies with ionic strength .
Neutrality is defined as the condition where ( H ) = ( OH ) (or the activities are equal).
Neutrality is defined as the condition where ( H ) = ( OH ) ( or the activities are equal ) . ( OH )