2Mg(s) + O2(g) ->
2MgO
2Na(s) + 2H2O(l) ->
2NaOH(aq) + H2(g)
Ca(s) + 2H2O(l) ->
Ca(OH)2(aq) + H2(g)
Zn(s) + 2HCl(aq) ->
ZnCl2(aq) + H2(g)
Zn(s) + 2H+ ->
Zn2+(aq) + H2(g)
Zn(s) + Cu(NO3)2(aq) ->
Zn(NO3)2(aq) + Cu(s)
Ca+HCl
fizzing on contact, gas formed, ca metal dissolved
Cu+HCl
NR
Mg + HCl
fizzing on contact, dissolved, warm to touch
Fe+HCl description
fizzed a little on contact, small bubbles, 2 layers top dirty white
Sn+HCl
NR
Zn+HCl
Fizzed on contact, slowly continued to fizz, metal slowly dissolved
Co+HCl description
Gas evolved, solution turned blue
Most reactive to least reactive: Sn Fe Cu Mg Ca Zn
Ca Mg Zn Fe Sn Cu
which of the oxides would be expected to be thermally unstable and decompose according to the equation? 2MO ->heat) 2M+O2
The group 2 oxides would be expected to decompose
Na+H20
NaOH + H2
Na + O2
2Na2O
Na + HCl
2NaCl + H2
Na + Ca2+
Na2+Ca
which is more reactive Fe2+ or Fe3+
Fe3+ high reactivity due to high valence states
What is oxidized and what is reduced? 2Al + 3Cl2 -> 2AlCl3
oxidized Al reduced Cl2 oxidizing Cl2 reducing Al
What is oxidized and what is reduced? FeS + 3NO3 + 4H -> 3NO + SO4 2- + Fe3+ 2H2O
oxidized FeS reduced NO3 oxidizing NO3 reducing FeS
What distinguishes a metal from a nonmetal?
Metals are high thermal and electrical conductivity, high luster, malleability, and ductility. Nonmetals have relatively high electron affinities and enter into chemical combination with metals by gaining electrons to become anions
What does ionization potential measure?
It measures the energy required to remove an electron from an atom in the gaseous state
What does electron affinity measure?
It measures the energy produced when an electron is added to a species in the gas phase and is the inverse of the ionization energy in a physical sense, but the values are not just of opposite sign because you are considering slightly different processes; in each case, they differ by one electron
Why must oxidation be accompanied by a reduction?
Because the oxidized element loses electrons and becomes more positive while the reduced element gains electrons and becomes more negative. Oxidization is always associated with a concomitant reduction, and the electron cannot just be given up to free space.
How does one determine the relative reactivities of metals?
By systematically observing the displacement reactions among metals and their cations, it is possible to determine the relative oxidation potentials of the metals. The metal with the lower reduction potential will reduce a cation of a metal with a higher reduction potential.
Zn+Cu2+
Zn2+ + Cu
Cu(s) + 4HNO3(aq) -> Cu(NO3)2(aq) + 2NO2(g) + 2H2O (l) what reaction?
redox
Cu(NO3)2+2NaOH->Cu(OH)2+2NaNO3 what reaction?
metathesis
Cu(OH2)->heat) CuO+H2O what reaction
dehydration
CuO+H2So4->CuSO4 + H2O what reaction
metathesis
CuSO4+Zn -> ZnSo4+Cu what reaction
redox
3CuSo4 + 2Al -> Al2(SO4)3 + 3Cu what reaction
redox
when does metathesis reactions proceed to completion
whenever one of the products is removed from the solution such as the formation of a gas or an insoluble substance
percent yield
recovered mass of Cu/initial mass of Cu x100
Cu + HNO3 description and chem equation
Cu(NO3)2+2NO2+2H2O releases gas and solution, turns blue, redox sol.
Cu(NO3)2 + NaOH -> description and chem equation
Cu(OH)2 + 2NaNO3 greenish, blueish color, metathesis solution
Cu(OH2) ->heat) description and chem equation
CuO(s) + H2O black solution, dehydration solution
allow black CuO to settle, decant liquid, add D.H20 and allow CuO to settle, decant. what are you removing? Then add H2SO4, what copper compound is present
NaNO3, CuSO4
CuSO4 + Zn what is present in solution, and what gas is found in this reaction
Cu(s), H2(g) since solution bubbled and became colorless
If 3.35 g of Cu(NO3)2 are obtained from allowing 2.25 g of Cu to react with excess HNO3, what is the percent yield of the reaction?
Cu+4HNO3->Cu(NO3)2+2H2O+2NO2
Cu(NO3)2=moles Cu
moles Cu=2.25g/63.5g/mol=0.0354mol
Cu(NO3)2=(0.0354mol)(188g/mol)=6.66g
%yield = 3.35x100/6.66g = 50.3%
What is the maximum percent yield in any reaction?
1
When Cu(OH)2(s) is heated, copper(II) oxide and water are formed. write a balanced equation
Cu(OH)2(s) ->heat) CuO+H20
When sulfuric acid and copper(II) oxide are allowed to react, copper(II) sulfate and water are formed. Write a balanced equation for this
H2SO4+CuO->CuSO4+H20
If your percent yield of copper were greater than 100% what are two plausible errors you may have made
the sample may have not had been fully dried and still ahve some h20 impurities mixed in with copper
consider the combustion of methane, CH4, what is the limiting reagent, how many moles of co2 can be made from this mixture? how many grams of co2? CH4(g) + 2O2(g) -> CO2(g) + 2H20 (g)
limiting reagent: oxygen
3mol O2 x 1mol CO2/2mol O2 = 1.5 mol CO2
1.5 mol CO2 x 44g CO2/1mol CO2 = 66g CO2
Suppose 8 g of CH4 is allowed to burn in the presence of 6.00g of oxygen. how much in grams, CH4, O2, CO2, and H2O remain after the reaction is complete?
8.00g CH4 (1molCh4/6gCH4) = .5 mol
(2molO2/1molCH4)=1.0 mol O2
6.00g O2 (1molO2/32g O2) = .1875 mol (1mol/2mol) =.09375 mol
CH4 = 6.50 g CO2=4.13g O2=0g H20= 3.375 g
define molarity
concentration measured by the number of moles of solute per liter of solution
how many ml of 6.0 M H2So4 are required to react with .80g of CuO
CuO(s) + H2SO4(aq) -> CuSO4 + H2O (l)
.80gCuO x 1mol/79.59CuO x 1molH2SO4/1molCuO= .0100628 mol H2SO4
6.0M H2SO4=10.0628mol/xmL solution = 1.677 mL
If 2g of Zn is allowed to react with 1.75 g of CuSO4, how many grams of Zn will remain after reaction is complete
CuSO4+Zn->ZnSO4+Cu
1.75x 1mol CuSO4/159.8g x 1molZn/1molSO4 = .01097mol Zn
.01902 mol Znx 1molZn/65.4g=.72g 2.00g-.72g = 1.28 g Zn remains
What is meant by limiting reagent
chemical that determines how far the reaction will go before the chemical in question gets used up