revision for test 1 (chapters 1-3) Flashcards
what is an isotope?
same number of protons, different number of neutrons
how do you calculate the atomic weight with abundance?
atomic weight = (mass x abundance) + (mass x abundance)
what is the mass percent?
it is the percentage of the amount of an element in a compound
what particular salts are soluble in water?
anything with : Na+, K+, NH4+, NO3-
how do you know if a reaction is a precipitation reaction?
if one of the poducts is not soluble in water (check in solubility chart)
how do you know if a reaction is an acid base one?
if the two reactants are an acid + a base, there has to be a transfer of H+ from acid to base
Which acids are the strong acids?
HCl, HBr, HI, HNO3, HCO4, H2SO4
which bases are the strong ones?
metals-OH, ex: Zn(OH)2, AgOH, LiOH
which acids are the weak ones?
anything-COOH, HF, H3PO4, HNO2
which bases are weak?
anything with nitrogen , ex: NH3
how do you know if there is gas forming reaction?
if there is a gas in the products
how is CO2 formed in a gas forming reaction?
carbonate with any acid
H2CO3 → H2O + CO2
how is SO2 formed in gas forming?
sulfite with any acid
H2SO4 → H2O + SO2
how is H2S formed in gas forming?
metal sulfide + acid
Na2S + 2HCl → 2NaCl + H2S
how is NH3 formed in gas forming?
ammonium + base
NH4+ + OH- → H2O + NH3
