Chemistry 10 Finals Review

Synthesis Reaction

(composition reaction) A + X → AX

% of water in hydrate

(mass of water in hydrate/ mass of hydrate) x 100%

Single-displacement Reaction

(replacement reaction) A + BX → AX + B or Y + BX → BY + X

evidence of a chemical reation

1. Evolution of energy as heat and light 2. Production of a gas 3. Formation of a precipitate. * A solid that is produced as a result of a chemical reaction in solution and that separates from the solution is known as a precipitate. 4. Color change

KMT and physical properties of gases

1. Expansion → They will completely fill any container they are placed in. 2. Gas particles move in all directions (#3) 3. No attractive forces (#4) 4. Fluidity → because the attractive forces of gases are insignificant, particles of a gas easily slide past one another and flow like a liquid. (both gases and liquids can be referred to as fluids) 5. No attractive forces (#4) 6. Low Density → particles are very much further apart than as solids or liquids 7. Particles are far apart (#1) 8. Compressibility → most of the volume of a gas is empty space, so squeezing them just makes them get closer together 9. Particles are far apart (#1)

balanced chemical equation

1. Identify the names of the reactants and the products, and write a word equation. *water → hydrogen + oxygen 2. Write a formula equation by substituting correct formulas for the names of the reactants and the products. *H₂O (l) → H₂ (g) + O₂ (g) (not balanced) 3. Balance the formula equation according to the law of conservation of mass. * Balance the different types of atoms one at a time. * First balance the atoms of elements that are combined and that appear only once on each side of the equation. * Balance polyatomic ions that appear on both sides of the equation as single units. * Balance H atoms and O atoms after atoms of all other elements have been balanced. 4. Count atoms to be sure that the equation is balanced. *2H₂O (l) → 2H₂ (g) + O₂ (g)

Double-displacement Reaction

AX + BY → AY + BX

Decomposition Reaction

AX → A + X

metal activity series

An activity series is a list of elements organized according to the ease with which the elements undergo certain chemical reactions. For metals, greater activity means a greater ease of loss of electrons, to form positive ions. For nonmetals, greater activity means a greater ease of gain of electrons, to form negative ions.

Combustion Reaction

In a combustion reaction, a substance combines with oxygen, releasing a large amount of energy in the form of light and heat.

molecular formula

Molecular formulas show exact number of each element in a compound 𝓍(empirical formula mass) = molecular formula mass *𝓍 is a small whole number integer

Kinetic Molecular Theory

all matter is made of particles, and these particles are ALWAYS in motion → energy of particles → forces of attraction between them (IMF) *Solids → Very Low energy, Very Strong IMF *Liquids → Low energy, Strong IMF *Gases 1. consist of large numbers of particles that are very far apart, relative to their size 2. collisions between gas particles and between particles and container walls are perfectly elastic - no energy is lost in these collisions 3. gas particles are in constant, rapid, random motion There are no forces of attraction between gas particles (no IMF's) 4. temperature of a gas depends on the average kinetic energy of the particles

hydrate formulas

hydrate → ionic salt that has water molecules trapped in its crystal structure hydrated ; containing water (CuSO4 ᐧ 5H2O) anhydrous ; containing no water (CuSO4) CuSO4 ᐧ 5H2O (copper(II) sulfate pentahydrate) → copper(II) sulfate with 5 moles of water ZnSO4 ᐧ 7H2O (zinc sulfate heptahydrate) → zinc sulfate with 7 moles of water Na2CO3 ᐧ 10H2O (sodium carbonate decahydrate) → sodium carbonate with 10 moles of water CaCl2 ᐧ 2H2O (calcium chloride dihydrate) → calcium chloride with 2 moles of water

empirical formula

the formula of a compound showing the smallest whole-number mole ratio of the various elements in the compound. <can be calculated from % composition data> a. assume that you have 100 g of sample (converts % directly to grams) b. calculate moles of each element (divide each by atomic mass) c. divide each by the smallest number of moles present to find the smallest whole number ratio (ratio calculated is the subscripts in the formula) d. round numbers close to whole numbers <calculated from mass composition data> a. calculate moles of each element (divide each by atomic mass) b. divide each by the smallest number of moles present to find the smallest whole number ratio (ratio calculated is the subscripts in the formula) c. round numbers close to whole numbers

molar mass

the mass of one mole of any substance (numerically equal to formula mass, but calculated in grams) - commonly used as conversion factor

chemical reaction

the process by which one or more substances are changed into one or more different substances *original substances of reaction → reactants *resulting substances of reaction → products according to the law of conservation of mass, *total mass of reactants = total mass of products

limiting reactant calculations (stoichiometry)

the reactant that runs out first

formula mass

the sum of atomic masses of all atoms in a chemical formula, in atomic mass units (amu)

significance of a chemical reation

1. The coefficients of a chemical reaction indicate relative, not absolute, amounts of reactants and products. H₂ (g) + Cl₂ (g) → 2HCl (g) 1 mol H₂ : 1 mol Cl₂ : 2 mol HCl 2. The relative masses of the reactants and products of a chemical reaction can be determined from the reaction's coefficients. * An amount of an element or compound in moles can be converted to a mass in grams by multiplying by the appropriate molar mass. 3. The reverse reaction for a chemical equation has the same relative amounts of substances as the forward reaction. * An equation gives no indication of whether a reaction will actually occur. * Chemical equations give no information about the speed at which reactions occur. * Equations do not give any information about how the bonding between atoms or ions changes during the reaction.

characteristics of a chemical reaction

1. The equation must represent known facts. 2. The equation must contain the correct formulas for the reactants and products. 3. The law of conservation of mass must be satisfied. * A coefficient is a small whole number that appears in front of a formula in a chemical equation.