I think that should be evaporation :)
Answer : Option A) HF.
Explanation : Assuming the complete question as per the attachment.
H-F bonds are formed because of hydrogen bonding between H atom and F atom and is considered to be strongest amongst the rest other options given.
As given in the table it is clear that the molar mass of HF molecule is the lowest. It shows that, when dispersion increases in the molecule molecular weight also increases.
Answer:
H⁺(aq) + OH⁻(aq) = H₂O(l)
Explanation:
To find the net ionic equation start by finding the balanced equation.
2HClO₄(aq) + Ba(OH)₂(aq) ⇒ 2H₂O(l) + Ba(ClO₄)₂(aq)
Then put it into the ionic equation.
2H⁺(aq) + 2ClO₄(aq) + Ba²⁺(aq) + 2OH⁻(aq) ⇒ 2H₂O(l) + Ba²⁺(aq) + 2ClO₄(aq)
Remove all the ions that do not change.
2H⁺(aq) + 2OH⁻(aq) ⇒ 2H₂O(l)
And reduce to the lowest common coefficient.
H⁺(aq) + OH⁻(aq) = H₂O(l)
Answer:
B) ) –1615.1 kJ mol^–1
Explanation:
since
SiO2(s) + 4 HF(aq) → SiF4(g) + 2 H2O(l) ∆Hºrxn = 4.6 kJ mol–1
the enhalpy of reaction will be
∆Hºrxn = ∑νp*∆Hºfp - ∑νr*∆Hºfr
where ∆Hºrxn= enthalpy of reaction , ∆Hºfp= standard enthalpy of formation of products , ∆Hºfr = standard enthalpy of formation of reactants , νp=stoichiometric coffficient of products, νr=stoichiometric coffficient of reactants
therefore
∆Hºrxn = ∑νp*∆Hºfp - ∑νr*∆Hºfr
4.6 kJ/mol = [1*∆HºfX + 2*(–285.8 kJ/mol)] - [1*(–910.9kJ/mol) + 4*(–320.1 kJ/mol)]
4.6 kJ/mol =∆HºfX -571.6 kJ/mol + 2191.3 kJ/mol
∆HºfX = 4.6 kJ/mol + 571.6 kJ/mol - 2191.3 kJ/mol = -1615.1 kJ/mol
therefore ∆HºfX (unknown standard enthalpy of formation = standard enthalpy of formation of SiF4(g) ) = -1615.1 kJ/mol