Chemical Reactions

chemical Reactions chemical Change reorganization original substances mannikin new substances with different formulas may or may not contain a change of state symbols spendd to describe chemical reply are known as a chemical equation Chemical equations do not have equal signs (=) they have an arrow Chemical Equations Must follow the Law of Conservation of Matter atoms can incomplete be created or destroyed during a chemical reaction What goes in mustiness come tabu Chemical Equations Reactants = Products same number of atoms of from each one element on each side of the reaction arrow Equations must be balanced other symbols (s)solid (l)liquid (g)gas (aq)aqueous, dissolved inwater Balancing Chemical Equations starting time check all ionic formulas to see if they are correct louver steps to balancing equations 1. Count the number of atoms of each element (or polyatomic ion) on the reactant side and then on the product side. You may requisite to use a chart o r table. 2. Determine which are out of balance these need to be balanced 3.Pick an element or polyatomic ion to start with Balance using coefficients. Do not use coefficients of 1 No changes may be made to the subscripts use least common multiples 5. Check and recheck Practice balancing these equations H2(g) + O2(g) H2O KCl + BaSO4 K2SO4 + BaCl2 Types of Chemical Reactions faction /Direct Combinationsynthesis 2Na(s) + Cl2(g) 2 NaCl(s) Single shifting single substitution anion ceaselessly replaces anion cation always replaces cation Mg + 2 HCl MgCl2 + H2 Complete the following Single switching (formula is correct) Al + CuSO4 Double Displacement 2 substitutions ion-exchange MgSO4 + BaCl2 BaSO4 + MgCl2 Types of Chemical Reactions Double Displacement What are the expected products of MgSO4 + BaCl2 Types of Chemical Reactions KOH + MgCl ( check formulas and complete) Decomposition HgO Hg + O2 (balance) 2 HgO 2 Hg + O2 carbonic acid in lab practise Oxi dation / Reduction oxidize iron into rust 4Fe + 3O2 ( 2Fe2O3 Oxidation reactions gibe O (or take aim H) Reduction reactions add H ( or remove O) Redox reaction Combination of oxidation and reduction Practice How legion(predicate) grams of diatomic oxygen (O2) are needed to make 4 moles of magnesium oxide (MgO) from magnesium ribbon (Mg)? Hint balance equation and use coefficient as mole. Energy in a Chemical Reaction Endothermic inflame in requires activation energy A + B + 100kcal = C + D Exothermic heat out A + B = C + D + 100 kcal