8B.5 Flashcards
what is thermal stability
the measure of the extent to which a compound decomposes when heated
why are group 2 nitrates and carbonates decompose but group 1 chlorides melt
- the charge in the group 2 cation is double the group 1 cation
- group 2 cation has a smaller ionic radius compared to group 1 cation
- the nitrate (NO3^-) and the carbonate (CO3^-2) anions are more complex than the chloride (Cl^-) anion
in decomposition what will happen to the nitrate ion
it will become a smaller more stable nitrate ion (NO2^-) and oxide ion (O^-2) by decomposing and releasing oxygen or nitrogen dioxide gas
in decomposition what will happen to the carbonate ion
it will become a smaller more stable oxide ion (O^-2) by decomposing and releasing carbon dioxide gas
what affects the stability of the nitrate and carbonate ions
by the size and charge of the cations
which element has the highest influence on the stability of the nitrate and the carbonate ions
beryllium
which element has the weakest influence on the stability of the nitrate and the carbonate ions
Cesium
what do we observe in the decomposition of group 1 and 2 nitrates
sometimes a brown flame from the nitrogen gas is released, and if the nitrate contains water of crystallization then steam would be observed as well
if brown flames weren’t observed in the decomposition of group 1 and 2 nitrates what does that mean
that the metal does have a weak influence on the nitrate ion and we would have a lesser decomposition
how can we detect oxygen when groups 1 and 2 decomposes
by using a glowing splint relights if oxygen present
what is the equation for the lesser decomposition of group 1 and 2 metals
metal nitrate —-> metal nitrite + Oxygen
how are nitrate and nitrite represented
by using oxidation number
Nitrate (V) is nitrate
nitrate(III) is nitirte
what is the equation for the greater decomposition of group 1 and 2 metals
metal nitrate —> metal oxide + nitrogen dioxide + nitrogen
when does the greater decomposition most likely occur
with a larger charge and a smaller cation
is group 1 metal greater or a lesser decomposition
lesser with only Li as an exception since it has the smallest radius
is group 2 a greater or a lesser decomposition
greater decomposition with Berlluim having the greatest decomposition
when groups 1 and 2 carbonates are heated what happens
they either decompose or not decompose
what are group 1 and 2 carbonates and nitrates look like
white solids
can there be any observation made in the decomposition of group 1 and 2 carbonates?
no observation can be made
is there decomposition in group 1 carbonates
no decomposition other than LI
is there decomposition in group 2 carbonates
yes all of em
what is the general formula of decomposition of metals
group 2: MCO3 ——> MO + CO2
group 1: M2CO3 ——> M2O + CO2
