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Types of chemical reactions – Part B. Dr. Chin Chu River Dell Regional High School. Unit objectives. There are millions of reactions. Can’t remember them all. Fall into several categories. Will learn 5 types. Will be able to predict the products.
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Types of chemical reactions – Part B Dr. Chin Chu River Dell Regional High School
Unit objectives • There are millions of reactions. • Can’t remember them all. • Fall into several categories. • Will learn 5 types. • Will be able to predict the products. • For some we will be able to predict whether they will happen at all. • Will recognize them by the reactants
exercise Balancing the following chemical equations: iron(s) + copper(II) sulfate(aq) copper(s) + iron(II) sulfate(aq) fluorine(g) + magnesium chloride(aq) chlorine(g) + magnesium fluoride(aq) sodium(s) + water(l) sodium hydroxide(aq) + hydrogen(g) Do you see the patterns?
Single-replacement reactions • Atoms of one element replace the atoms of another element in a compound. • General Equation: AB + C ® BC + A • Animation: • Reactants must be an element and an ionic compound • Products will be a different element and compound.
Single-replacement reactions • Metal replaces metal ions (and hydrogen). • Zn + HCl • Think water (H2O) as HOH. • Elemental metal replaces H and combine with hydroxide. • Na + H2O
Single-replacement reactions • Demonstrations: • + • + • When two compounds are mixed together, NO guarantee a chemical reaction will occur! • Some elements are more reactive than the others. • More reactive ones replace the less reactive ones. • REACTIVITY SERIES. • There are two reactivity series, one for metals and the other for halogens.
Single-replacement reactions Decreasing Reactivity • METALS: • Lithium (cont.) • Rubidum Copper • Potassium Silver • Calcium Platinum • Sodium Gold • Magnesium • Aluminum • Manganese • Zinc • Iron • Tin • Lead • HALOGENS: • Fluorine • Chlorine • Bromine • Iodine • Single-replacement reaction only proceeds when the element is higher on the reactivity list than the ion.
Single-replacement reactions • Examples: • Reactions involving metallic elements as reactants. • CaCl2(aq) + Zn(s) x • Zinc is lower on the reactivity list than Ca ion. No reaction. • 3ZnCl2(aq) + 2Al(s) 3Zn(s) + 2AlCl3(aq) • Aluminum is higher on the reactivity list than zinc. Single-replacement reaction proceeds.
Single-replacement reactions • Examples: • Reactions involving halogen elements as reactants. • NaCl(aq) + Br2(l) x • Bromine is lower on the reactivity list than chlorine. No reaction. • 2NaI(aq) + Br2(l) I2(s) + 2NaBr(aq) • Bromine is higher on the reactivity list than iodide ion. Single-replacement reaction proceeds.
Single-replacement reactions • Exercises: • Predict whether the following single-replacement reactions will take place. If yes, write down the balanced chemical equations. • Cu(s) + AgNO3(aq) • Fe(s) + ZnBr2(aq) • F2(g) + NaCl(aq) • Zn(s) + FeBr2(aq) • Mg(s) + CaCl2(aq) • Br2(l) + LiI(aq) • Cl2(g) + KBr(aq)