Chemical/Physical Properties & pH 7.P.2B.3 Analyze and interpret data to compare the physical properties, chemical properties (neutralization to form a salt, reaction with metals), and pH of various solutions and classify solutions as acids or bases.

Physical Properties You should already know that: Physical properties can be observed without changing the composition of the substance.

Chemical Properties You should already know that: Chemical properties can ONLY be observed by changing the composition of the substance, forming new substances.

pH Scale A tool that is used to measure how acidic or alkaline (basic) something is. Measures from 0 to 14.

Acids Acidic solutions have a pH between 0 and 6. Chemical formulas usually start with H Examples of acids:

Bases Alkaline (basic) solutions have a pH between 8 and 14. Chemical formulas usually end in OH Examples of bases:

Neutrals Neutral solutions have a pH of 7. Example of neutral:

Chemical Properties of ACIDS React with some metals to give off a gas Neutralization occurs when acids and bases react with each other. They can form a salt and usually water.

Chemical Properties of ACIDS React with blue litmus paper turning it red Does not react with red litmus paper and the litmus paper will remain red. Doesn’t react with phenolphthalein

Physical Properties of ACIDS Tastes sour Sticky texture

Chemical Properties of BASES Neutralization occurs when bases and acids react with each other. They can form a salt and usually water. React with red litmus paper turning it blue.

Chemical Properties of BASES Does not react with blue litmus paper and the litmus paper will remain red. Reacts with phenolphthalein turning it magenta (pink)

Physical Properties of BASES Tastes bitter Slippery texture

Chemical Properties of NEUTRALS Are formed when neutralization occurs between acids and bases. Neither an acid nor a base.

Chemical Properties of NEUTRALS Reacts with litmus paper turning it violet. Reacts with phenolphthalein turning it magenta (pink).

Indicators Substances that can be used to determine if a solution is acidic, basic, or neutral. Litmus Paper Phenolphthalein pH Paper

Litmus Paper Has a special dye on it that changes colors in the presence of an acid or base. Blue litmus paper turns red in an acid, and stays blue in a base. Red litmus paper turns blue in a base, and stays red in an acid.

Phenolphthalein Is used to test for the presence of a base. It is a colorless chemical that turns magenta (bright pink) in a base, and stays colorless in neutral or acidic solutions.

pH paper Has a range of colors depending on the pH of the solutions The color of the paper is compared to the chart on the vial to determine the pH