Describe pure substances and physical mixtures.
Pure substances are chemical combinations of matter in definite (fixed) proportions. Aluminum, salt, and distilled water are examples. Physical mixtures are physical combinations of matter in any proportions. They have no definite or constant composition—the composition of the mixture varies according to who prepares the mixture. An example is hairstyling spray.
What are the differences between solutions, suspensions, and emulsions?
A solution is a stable, uniform mixture of two or more substances. An example of a solution is salt water. A suspension is an unstable physical mixture of undissolved particles floating in a liquid. An example of a suspension is oil and vinegar salad dressing, in which the oil droplets are suspended in the vinegar. An emulsion is an unstable mixture of two or more substances that normally will not stay mixed without a special ingredient called an emulsifier. An example of an emulsion is hand lotion.
pH is the abbreviation used for potential hydrogen. The pH scale measures the acidity and alkalinity of a substance. It has a range of 0 to 14, with 7 being neutral. A pH below 7 is an acidic solution and a pH above 7 is an alkaline solution.
Explain neutralization reactions and why they are an important part of beauty services.
Neutralization reactions occur when an acid is mixed with an alkali in equal proportions, balancing the total pH and forming water and a salt. Neutralizing products help to return hair or skin back to its natural pH, which is an important step in beauty services needed to return the body to equilibrium.
What are guidelines for properly storing chemicals?
List all of the categories found on a Safety Data Sheet.