chemistry review sheets
Order by
45 terms
Terms | Definitions |
|---|---|
 catalyst | a substance that speeds a chemical reaction without itself being changed |
| coefficient | in a chemical equation, a number to the left of each reactant and product that shows the relative amount of each substance involved int he reactions (for example, the 3 in 3H20) |
| chemical equation | a group of symbols denoting a chemical reaction |
| chemical reaction | a change in which substances are converted to different substances that have different properties |
| concentration | generally, the proportion of a solute dissolved in a solvent; specifically, the milliliters of solute, plus enough solvent to total 100mL of solution |
| law of conservation of mass | the mass of all substances involved in a chemical change will be the same after the change; matter is neither created nor destroyed during a chemical change |
| oxidation number | a positive or negative number that indicates an element's ability to form a compound |
| endothermic reaction | a chemical reaction that requires the addition of heat energy to proceed; thus the reaction absorbs heat from its surroundings |
| exothermic reaction | a chemical reaction that releases heat energy |
| products | in a chemical reaction, the substances formed by the reaction |
| reactants | in a chemical reaction, the substances you start with before the reaction |
| reaction rate | how fast or how slow a reaction takes place |
| toxic | describes any substance that can injure living tissue; a poison |
| polyatomic ion | a group of covalently bonded atoms in which the whole group has a positive or negative charge |
| binary compound | a chemical compound composed of two elements (for example, sodium chloride) |
| chemical bond | a force that holds together the atoms in a compound |
| chemical formula | a precise statement of the elements in a compound and their ratio |
| chemically stable | describes an atom whose outer-most energy level is filled with electrons, so that it does not form compounds under normal conditions (for example, helium, neon) |
| corrosive | describes any substance that attacks and alters metals, human tissue, or other materials |
| examples of corrosive substances | battery acid, bleach, and cleaners for ovens, toilets, and drains |
| covalent bond | a type of chemical bond formed by atoms when they share electrons; this force holds together molecules in gases like oxygen and nitrogen, and in compounds like water |
| polar molecule | a molecule in which one atom has a stronger attraction for electrons than the other, giving the molecule a positive end and a negative end |
| ion | an atom having an electrical charge, either positive or negative |
| ionic bond | a type of chemical bond that holds together compounds of oppositely charged ions |
| nonpolar molecule | a molecule in which the atoms have an equal attraction for electrons, so the molecule is not polarized into positive and negative ends |
| acid | a substance that produces hydrogen ions (H+) when dissolved in water; this lowers the solution's pH below 7 |
| base | a substance that produces hydroxide ions (OH-) when dissolved in water; this raises the solution's pH above 7 |
| double displacement reaction | a chemical reaction in which the positive ions in two or more substances trade places |
| decomposition reaction | a chemical reaction in which a substance breaks down into two or more simpler substances |
| synthesis reaction | a chemical reaction in which two or more substances combine to form a different substance |
| neutralization reaction | a chemical reaction between an acid and a base; the acid's hydronium ions combine with the base's hydroxide ions to produce water, and the acid's negative ions combine with the base's positive ions to produce a salt |
| salt | a compound containing negative ions from an acid combined with positive ions from a base; forms during a neutralization reaction |
| electrically neutral | a compound having no overall electrical charge because the total positive charge equals the total negative charge |
| chemically neutral | a solution that is neither acidic nor basic |
| single replacement reaction | a chemical reaction in which one element replaces another element in a compound |
| inhibitor | a substance that slows down a chemical reaction |
| pH | a measure of hydronium ion concentration in a water solution, expressed on the scale from 0-14. From 7 down to 0, a solution is increasingly acidic; at 7 it is neutral (water); from 7 up to 14 it is increasingly basic |
| properties of acids | taste sour are electrolytes are corrosive react with certain compounds, called indicators, to produce a predictable change in color |
| properties of bases | crystalline solids in the pure, undissoved state corrosive slippery and bitter in solution solutions are electrolytes react with indicators or produce predictable changes in color |
| what determines the strength of an acid or base | how completely a compound is pulled apart to form ions when dissolved in water |
| a strong acid | ionizes almost completely in solution |
| a weak acid | only partly ionizes in solution |
| a strong base | dissociates completely in solution |
| chemical formula | tells what elements it contains and the ratio of the atoms of those elements |
| why chemical bonding occurs | because losing, gaining, and sharing electrons are the means by which atoms become stable |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.