In chemistry, pH () (potential of hydrogen) is a numeric scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the molar concentration, measured in units of moles per liter, of hydrogen ions. More precisely it is the negative of the logarithm to base 10 of the activity of the hydrogen ion. Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic. Pure water is neutral, at pH 7 (25°C), being neither an acid nor a base. Contrary to popular belief, the pH value can be less than 0 or greater than 14 for very strong acids and bases respectively. 

pH measurements are important in agronomy, medicine, biology, chemistry, agriculture, forestry, food science, environmental science, oceanography, civil engineering, chemical engineering, nutrition, water treatment and water purification, as well as many other applications. 

The pH scale is traceable to a set of standard solutions whose pH is established by international agreement. Primary pH standard values are determined using a concentration cell with transference, by measuring the potential difference between a hydrogen electrode and a standard electrode such as the silver chloride electrode. The pH of aqueous solutions can be measured with a glass electrode and a pH meter, or an indicator. QUESTIONS:

Q1:
1. What does pH stand for?
2. What is meant by the acronym pH?
3. How can pH be defined?
Q2:
1. What kind of scale is used for pH?
2. What scale does pH employ?
3. On what kind of scale is pH measured?
Q3:
1. What does pH specify?
2. What is measured by pH?
3. What does a pH value determine?
Q4:
1. What is pH the negative of?
2. pH value is the negative of what?
3. State what pH is the negative of.
Q5:
1. What is pH measured in?
2. What unit is used to measure pH?
3. How is pH value determined?
Q6:
1. What are things with pH less than 7 called?
2. What is the word to describe something with a pH lower than 7?
3. How can something with a pH lower than 7 be described?
Q7:
1. What is something with a pH above 7?
2. What is the word to describe something with a pH higher than 7?
3. How can something with a pH higher than 7 be described?
Q8:
1. What is the pH of water?
2. What word describes the pH of water?
3. What pH value is given to water?
Q9:
1. What degree of water is used to measure its pH?
2. What degree of water measures is pH?
3. Which degree of water is used to determine its pH?
Q10:
1. 
2. 
3. 
Q11:
1. Is it possible for pH to be less than 10?
2. Do pH values below 10 exist?
3. Can something have a pH of less than 10?
Q12:
1. Is it possible for pH to be less than 0?
2. Do pH values below 0 exist?
3. Can something have a pH of less than 0?
Q13:
1. Is it possible for pH to be more than 14?
2. Do pH values over 14 exist?
3. Can something have a pH of more than 14?
Q14:
1. How is the pH of aqueous solutions measured?
2. What measures the pH of acqeous solutions?
3. How is the pH of an aqueous solution determined?
Q15:
1. How is the pH of aqueous solutions measured other than with a pH meter?
2. What measures the pH of acqeous solutions, besides a pH meter?
3. How is the pH of an aqueous solution determined, apart from by a pH meter?
