Verified Solution • 2025–26 Session
moderate
QAIPMT-2007-Ch-2301: NEET 2007 Chemistry - Class 11 AIPMT-2007-Ch-2301 Solution: An element X has the following isotopic composition: \(^{200}X: …
An element X has the following isotopic composition: . The weighted average atomic mass of the naturally occurring element X is closest to 201 amu 202 amu 199 amu 200 amu
Multiple Choice Options
- A +X 3 kJ mol _ 1
- B _ X 4 kJ mol _ 1
- C +X 1 kJ mol _ 1
- D _ X 2 kJ mol _ 1
Step-by-Step Verified Solution
Chemical equation for the formation of H 2 O(l)
is
H 2(g) + 1/2O 2(g) = H 2 O (l)
Because enthalpy of formation of a compound is
the heat absorbed or released when one mole of this
substance is formed from its constituent elements.
Thus, enthalpy of formation of H 2 O is �X 2 kJ mol �1
where negative sign shows that the reaction is
exothermic.
Equation (i) represents nutralisation reaction.
Equation (iii) represents hydrogenation reaction.
Equation (iv) represents combustion reaction.