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6.8 – NOTES Metal Reactivity Trends. Metal Reactivity. Copper reacts with oxygen to turn black, but the reaction needs to be heated. 2Cu(s) + O 2 (g) 2CuO(s) Copper (II) Oxide Copper black. Magnesium reacts with oxygen, but when heated burns in a flash of light
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Metal Reactivity • Copper reacts with oxygen to turn black, but the reaction needs to be heated. • 2Cu(s) + O2(g) 2CuO(s) Copper (II) Oxide • Copper black
Magnesium reacts with oxygen, but when heated burns in a flash of light • 2Mg (s) +O2(g) 2MgO(s) + light Magnesium Oxide
Gold will not react with oxygen, even when heated • Different metals have different levels of reactivity, just as you saw in the Relative Reactivities of Metals Lab • How would you rank the reactivities of Cu, Mg and Au? • Most Mg, Cu, Au least
Activity series • Ranking the elements according to their chemical reactivities • See handout • The activity series predicts if chemical reactions will occur • Most reactive at top • Least reactive at bottom
How do we know if a reaction will occur? • By looking at relative reactivities on the Metal Activity Series. • 1. Identify if the reaction will occur. 2. Predict the Products. • 1. K + Ag2S • 2. Br2 + NaCl • 3. Pb (IV) + NiCl2
Use your activity series and periodic table to answer the following questions • Will Pb metal replace Ag+ ions? • Yes, Pb is above Ag, it is more reactive
2. What trend in metallic reactivity is found as you move from left to right across a horizontal row (period) of the periodic table? (Hint: compare the reactivity of sodium with magnesium and aluminum.) • Metal reactivity goes down as you move L to R
3. Where are the most reactive metals on the periodic table found? • Top left corner alkali and alkaline earth metals
4. Where are the least reactive metals located? • Transition Metals
5. Will iron (Fe) react with a solution of lead (II) nitrate (Pb(NO3)2)? • Fe + PB(NO3)2 yes, reactions happens, Fe is above Pb
6. Will platinum (Pt) metal react with a lead (II) nitrate solution? • Pt + Pb(NO3)2 no, Pt is below Pb
7. Explain your answers to questions 5 and 6. • Element is above ion, reaction will happen • Element is below ion, reaction won’t happen
Use specific examples from the activity series in your answers to these two questions: • Are the least reactive metals also the least expensive metals? • No, Au, Pt, Ag are least reactive but expensive .
If not, what other factor(s) might influence the market value of a metal? • Abundance, fashion, preference, strength, how easily is it mined.