Explanation:
Given
The enthalpy of formation of RbF (s) is –557.7kJ/mol
The standard enthalpy of formation of RbF (aq, 1 m) is –583.8 kJ/mol
The enthalpy of solution of RbF = Enthalpy of RbF (aq) - Enthalpy of formation of RbF (s)
= -583.8 - (-557.7) kJ/mol
= -26.1 kJ/mol
The enthalpy is negative which means that the temperature will rise when RbF is dissolved.
Answer:
The products react to reform the original reactants
E.g. Haber process of ammonia production
Answer:
pH = 12.65
Explanation:
From the given information:
number of moles =mass in gram / molar mass
number of moles of KOH = mass of KOH / molar mass of KOH
number of moles of KOH = 0.251 g / 56.1 g/mol = 0.004474 mol
For solution :
number of moles = Concentration × volume
concetration = number of moles/ volume
concetration = 0.004474 mol / 0.100 L
concetration = 0.04474 M
We know that 1 moles KOH result into 1 mole OH⁻ ions
Therefore, Molarity of OH⁻ = 0.04474 M
Now,
pOH = -log[OH⁻]
pOH = -log (0.04474) M
pOH = 1.35
Similarly,
pH + pOH = 14
pH = 14 - pOH
pH = 14 - 1.35
pH = 12.65
