Science 10: Chemical Reactions, Acids, Bases, and Salts

Flashcards covering the characteristics of physical and chemical changes, indicators of chemical reactions, biochemistry of proteins, and the properties of acids, bases, and salts.

Physical Change

A change that affects only the form or appearance of a substance, where the composition remains the same and no new substance is formed.

Chemical Change

A process where a substance turns into one or more new substances, involving a rearrangement of atoms.

Chemical Reaction

A process involving the breaking and forming of chemical bonds to create new substances with new properties.

Indicators

Signs that tell scientists a chemical reaction has occurred, often categorized by the acronym C-P-G-T (Color, Precipitate, Gas, Temperature).

Precipitate

A solid that forms when two liquids are mixed during a chemical reaction, such as the reaction between $AgNO_3$ and $NaCl$.

Exothermic Reaction

A chemical reaction that releases energy as heat and light, such as burning.

Endothermic Reaction

A chemical reaction that absorbs heat from its surroundings, such as cooking.

Ovalbumin

A soluble protein found in egg whites that becomes an insoluble precipitate when it is denatured by a substance like alcohol.

Casein

A milk protein that precipitates into solid curds when an acid, such as vinegar, alters its electrical charge.

Denaturation

The chemical process where a protein loses its natural shape and function due to factors like acid or alcohol, as seen in the preparation of Kinilaw.

Curcumin

A molecule found in turmeric that acts as a pH indicator, reflecting red light in basic solutions and yellow light in acidic or neutral solutions.

Anthocyanins

Molecules in the Butterfly Pea flower that physically reorganize and change color when reacting with acids or bases.

Acid

A substance that produces hydrogen ions ($H^+$) when dissolved in water, tastes sour, and decreases pH below $7$.

Base

A substance that produces hydroxyl ions ($OH^-$) in water, feels slippery like soap, and has a pH value greater than $7$. Or alkaline.

Salt

A compound formed from the reaction of an acid and a base, typically neutral in pH.

Neutralization

The chemical reaction between an acid and a base that produces salt and water, such as $HCI + NaOH \rightarrow NaCl + H_2O$.

Natural Indicators

Indicators derived from plants and natural materials, such as Litmus, Turmeric, Red cabbage juice, or Hibiscus.

Synthetic Indicators

Man-made chemicals used in laboratories for testing, such as Phenolphthalein, Methyl orange, and Bromothymol blue.

Phenolphthalein

A synthetic indicator that is colorless in acidic or neutral solutions and turns pink or fuchsia in basic solutions.

Universal Indicator

A mixture of several indicators that shows a wide range of colors across the pH scale to provide an approximate pH value.

pH Scale

A scale from $0$ to $14$ used to measure acidity or alkalinity, where $7$ is neutral, below $7$ is acidic, and above $7$ is alkaline.