Metal Reactivities Lab – Introduction investigate the relative reactivity (tendency to ______________) of eleven metals if atoms of elements are reactive, they react with other _____________________ to form _______________________ *****KEY******* (relatively) reactive metals tend to be ________________________ (relatively) unreactive metals tend to be ______________________ chchchchange elements compounds in compounds pure

metal atoms lose OR gain electrons when they react with nonmetals (the nonmetal atoms lose OR gain electrons) **KEY** so,… in compounds, the metal is found as a _________________________ the nonmetal is found as a ______________________ example: pure sodium – Na and pure chlorine – Cl react to form the compound sodium chloride Na Cl Na+ and Cl- (or NaCl) positive ion (cation) negative ion (anion) e-

metal atoms lose OR gain electrons when they react with nonmetals (the nonmetal atoms lose OR gain electrons) (lose/gain enough electrons to get a _______________) **KEY** so,… in compounds, the metal is found as a _________________________ the nonmetal is found as a ______________________ predict the easier / harder it is to lose electrons the more / less reactive the metal the easier / harder it is to gain electrons the more / less reactive the nonmetal full outer shell positive ion (cation) negative ion (anion) METALS NONMETALS MOST LEAST LEAST MOST

Li, Na, K, Mg, Ca, Fe, Cu, Ag, Zn, Al, and Pb METALS NONMETALS MOST LEAST LEAST MOST you will carry out a series of reactions to establish the relative reactivity of the eleven metals Li, Na, K, Mg, Ca, Fe, Cu, Ag, Zn, Al, and Pb then, you will compare what you observe experimentally to what you would predict based on trends AND offer explanations for deviations of the observed reactivity from the predicted reactivity

PART A – Ag, Cu, Fe, Zn, Pb Test the relative reactivities of these metals based on the principle that the more reactive metal will tend to be in a compound OR pure the less reactive metal will tend to be in a compound OR pure Example: Copper (Cu) and Zinc (Zn) Cu(SO4) (aq) + Zn (s) observe Zn(SO4) (aq) + Cu (s) observe focus on Cu(SO4) (aq) + Zn (s) copper in a compound pure zinc pure copper zinc in a compound the change (reaction) happens, because copper “prefers” to be ______ _____________________ and zinc “prefers” to be ____________ __________________ pure copper is less reactive in a compound zinc is more reactive

Cu(SO4) (aq) + Zn (s) Cu (s) + Zn(SO4) (aq) copper in a compound the less reactive metal ends up pure pure zinc the more reactive metal ends up in a compound pure copper zinc in a compound the change (reaction) happens, because copper “prefers” to be pure _____________________ and zinc “prefers” to be in a compound ___________________ copper is less reactive zinc is more reactive this type of reaction is called single displacement a more reactive element displaces a less reactive element from a compound (the two elements swap being pure / in a compound) this type of reaction is the basis of some batteries…..

Single displacement reactions and batteries Cu(SO4) (aq) + Zn (s) Cu (s) + Zn(SO4) (aq) copper in a compound zinc in a compound the less reactive metal ends up pure the more reactive metal ends up in a compound pure zinc pure copper Cu2+ Zn2+ when pure metal atoms react, they lose electrons cations of the metal in a compound Cu loses 2 e- Cu2+ Zn loses 2 e- Zn2+ for a metal cation in a compound to become a pure metal atom, the cation must gain electrons Cu2+ gains 2 e- Cu Zn2+ gains 2 e- Zn Zn2+ + Cu 2e- Zn + Cu2+

Phew… right….. so,….. for PART A principle – the more reactive metal “wants” to be in a compound the less reactive metal “wants” to be pure to test for the relative reactivity of two metals, - start with one pure and one in a compound - combine - look for evidence of the “swap” (single displacement) key evidence set up looks like….

PART B and C – (also) Single displacement reactions Test the relative tendency of a metal to displace hydrogen from a compound PART B – Mg, Zn, Pb, Al example: Mg (s) + HCl (aq) ??  ?? H2 ( ) + evidence ? _________________ PART C – Li, Na, K, Ca, Mg example: Mg (s) + H2O (l) ??  ?? H2 ( ) + (hydrogen is acting like a metal) BUBBLES BUBBLES In either part (reacting with HCl / H2O) how can you tell which metal is MORE reactive?

Metal Reactivities Lab – Postlab metal atoms lose OR gain electrons when they react with nonmetals (the nonmetal atoms lose OR gain electrons) **KEY** so,… in compounds, the metal is found as a _________________________ the nonmetal is found as a ______________________ Reactivity (of metal atoms) depends on: 1. _____________________________ which depends on ____________________________________________ 2. _____________________________ to get ______________________________________________________ cationx+ aniony- opposite charges attract (bond) compound positive ion (cation) negative ion (anion) how easy it is to lose electrons (IE) atomic size (and sublevel configuration) # of electrons to lose a FOS (or full or ½-full sublevel) combination of these two gives ________________________ the lower this value, (predict) the ____________ reactive total IE MORE

silver Ag copper Cu zinc Zn METALS NONMETALS MOST LEAST LEAST MOST silver Ag copper Cu zinc Zn predict ____________________________________ observe ___________________________________ so,…. there must be something else going on other than ______________________________ Ag more reactive than Cu more reactive than Zn Zn more reactive than Cu more reactive than Ag hmmmmmmm………. how easy it is to lose electrons total IE # of electrons to lose to get FOS (or some other stable e- configuration)

silver Ag copper Cu zinc Zn predict ____________________________________ observe ___________________________________ so,…. there must be something else going on other than ______________________________ Ag more reactive than Cu more reactive than Zn Zn more reactive than Cu more reactive than Ag hmmmmmmm………. how easy it is to lose electrons total IE # of electrons to lose to get FOS (or some other stable e- configuration) ***KEY*** _________________________________ but, by definition, _____________________________ there must at least be __________________________ for ISOLATED atoms a reaction cannot happen with an ISOLATED atom at least two atoms to react well let’s consider what happens when an isolated atom becomes un-isolated….

isolated atom isolated You to the chalkboard…..

silver Ag copper Cu zinc Zn predict ____________________________________ observe ___________________________________ so,…. there must be something else going on other than ______________________________ Ag more reactive than Cu more reactive than Zn Zn more reactive than Cu more reactive than Ag hmmmmmmm………. how easy it is to lose electrons total IE # of electrons to lose to get FOS (or some other stable e- configuration) ***KEY*** _________________________________ but, by definition, _____________________________ there must at least be __________________________ for ISOLATED atoms a reaction cannot happen with an ISOLATED atom at least two atoms to react *****KEY***** any other “stuff” around will influence the behavior (reactivity) of the atom(s) of interest what other “stuff” is around?

especially the presence of water Environmental Factors and Metal Reactivity ex: Copper vs Silver observe: ____________ is more reactive than _______________ predict: based on atomic size _________________________ because ______________________________________________ based on # of electrons to lose _______________________ Ag loses _________ ____________ total IE = 1st IE = __________________ Cu loses __________ ____________ total IE = 1st IE + 2nd IE = ___________________ BUT….. so, ______________________________________________ predictions are based on ___________________________ for a reaction to occur ____________________________________________ ______________________________________________________________________ copper silver silver more reactive than copper (trends) silver atoms larger than copper silver more reactive than copper 1 e- Ag+ 733 kJ/mol Ag total IE 2 e- Cu2+ 2712 kJ/mol Cu there must be some other factor(s) single, ISOLATED atoms can’t be… need (at least) two atoms especially the presence of water the presence of any other substance, the Temperature, the pressure,… (the environment) all effect the reactivity of atoms

Cu (s) + 2 Ag(NO3) (aq) 2 Ag (s) + Cu(NO3)2 (aq) H ** ** Cu (s) + 2 Ag(NO3) (aq) 2 Ag (s) + Cu(NO3)2 (aq) H O H O H O H O metal in a compound must be a(n) _________ Ag+ Cu2+ (NO3)- H O (NO3)- (NO3)- H O cation H O so nitrate must be a(n) __________ H O anion water is ___________ the O side is slightly (-) so, sticks to _________________ the H side is slightly (+) so, sticks to ________________ water will stick more tightly to ions that have higher or lower charge Cu2+ OR Ag+ water will stick more tightly to ions that are smaller or larger STICKY cations anions

to unstick (____________) ______________________________________ so, to stick (_______________) must _______________________________________ so, when water sticks to a metal cation, the cation (and water) become more _____________ so, water stabilizes _________ AND water stabilizes ________ stabilize = __________________________ so, ______________________________________ which is the same as saying water encourages the ____________ to form which is the same as saying water encourages the metals to ____________ so, __________________________________________________________ pull apart takes energy so, becomes less stable come together release energy so, becomes more stable stable Cu2+ Ag+ (because water sticks to them) metal cations = metals in ___________ compounds encourages to happen water encourages the cations to form compounds react water increases the reactivity of ALL metals reactivity metals in the presence of water pure metals

water increases the reactivity of ALL metals metals in the presence of water pure metals water sticks more tightly to Cu2+ OR Ag+ ? Why? so, water _______________ the reactivity of ___________________ moreso than the reactivity of ____________________________ because, water stabilizes the _________ cation (__________ in a ___________) moreso than it stabilizes the _______ cation (__________ in a ___________) copper ions are smaller and have higher charge than silver ions increases (the pure metal) copper (the pure metal) silver copper copper compound silver silver compound

water increases the reactivity of ALL metals water _______________ the reactivity of ___________________ moreso than the reactivity of ____________________________ because, water stabilizes the _________ cation (__________ in a ___________) moreso than it stabilizes the _______ cation (__________ in a ___________) increases (the pure metal) copper (the pure metal) silver copper silver compound Cu Ag metals in the presence of water reactivity pure metals Ag Cu

Why is Copper more reactive than Silver ? Cu2+ (g), 2 Cl (g) 1st + 2nd IE Cu (1st EAE Cl)  2 Why is Copper more reactive than Silver ? Cu2+ (g), 2 Cl- (g) the presence of chlorine (chloride) influences the stability of the product therefore the reactivity… the presence of water influences the stability of the product even more therefore the reactivity even more… Ag+ (g), Cl (g) 1st EAE Cl 1st IE Ag Ag+ (g), Cl- (g) Cu (g), 2 Cl (g) isolated atoms isolated atoms Ag (g), Cl (g) Ag+Cl- (aq) Ag (s), ½ Cl2 (g) Cu (s), Cl2 (g) Cu2+Cl2- (s) Ag+Cl- (s) Cu2+Cl2- (aq)

The environment (temperature, pressure, and any other “stuff”) affects the reactivity of metals (or any substance) **especially the presence of water Water sticks to cations (metal ions in compounds) so, water stabilizes the metal _____________________ and therefore, ___________________ the reactivity (of all metals above the reactivity w/o water present). Water will increase the reactivity to a greater degree for metals that form _____________ and _______________________ cations in a compound increases smaller more highly charged

most reactive nonmetals smallest atoms - easiest to gain e- Summary of Trends across a period atoms get smaller ions get smaller down a group atoms get larger ions get larger to get a FOS # e- to lose # e- to gain more less same most reactive nonmetals smallest atoms - easiest to gain e- fewest e- to gain to get a FOS IE harder to lose e- easier to gain e- EAE metals nonmetals most reactive metals (aside from noble gases) least reactive largest atoms - easiest to lose e- fewest e- to lose to get a FOS IE easier to lose e- harder to gain e- EAE

the reactivity of these metals more Summary of Trends across a period atoms get smaller ions get smaller IE so,… water increases the reactivity of these metals more EAE to get a FOS # e- to lose metals nonmetals more less most reactive metals form smaller ions higher charge (aside from noble gases) least reactive form larger ions lower charge down a group to get a FOS atoms get larger than it increases the reactivity of these metals ions get larger # e- to lose same IE EAE opposite the trend for reactivity for isolated atoms !

Why is Copper more reactive than Silver ? Cu2+ (g), 2 Cl (g) 1st + 2nd IE Cu (1st EAE Cl)  2 Why is Copper more reactive than Silver ? Cu2+ (g), 2 Cl- (g) Ag+ (g), Cl (g) 1st EAE Cl 1st IE Ag Ag+ (g), Cl- (g) Cu (g), 2 Cl (g) isolated atoms Ag (g), Cl (g) isolated atoms Ag (s), ½ Cl2 (g) Cu (s), Cl2 (g)