Answer : Normally in any chemical reaction, if the enthalpy change i.e. ΔH is positive which means it is greater than zero then it can be called as an Endothermic Reaction.
Whereas, the system under study is absorbing heat that is produced during the reaction. So if ΔH is found to be positive then it can be called as endothermic reaction.
To solve the problem, we assume the sample to be ideal. Then, we use the ideal gas equation which is expressed as PV = nRT. From the first condition of the nitrogen gas sample, we calculate the number of moles.
n = PV / RT
n = (98.7x 10^3 Pa x 0.01 m^3) / (8.314 Pa m^3/ mol K) x 298.15 K
n = 0.40 mol N2
At the second condition, the number of moles stays the same however pressure and temperature was changed. So, the new volume is calculated as follows:
V = nRT / P
V = 0.40 x 8.314 x 293.15 / 102.7 x 10^3
V = 9.49 x 10^-3 m^3 or 9.49 L
The chemical formula of aluminium nitrate is - Al(NO₃)₃
cation is Al³⁺
anion is NO₃⁻
One Al atom binds to three nitrate groups
the options given are
2. <span>It has three aluminum (Al) atoms
this is incorrect as there's only one Al atom
3. </span><span>It has one NO3 group.
this is incorrect as there are three nitrate groups
4. </span><span>It has nine nitrogen (N) atoms
there are only 3 N atoms therefore this too is incorrect
</span>therefore the correct answer is -
It has three NO₃<span> groups
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