Substance A is ionic because in molten and aqueous solution conduct electricity and dissolves in water. This is because it dissociate in ions and ion conduct electicity and dissolve in polar molecules (water). Ionic bond is very strong (high melting point).
Substance B non polar covalent, because it is not dissolve in polar molecules and has weak intermolecular forces (low melting point).
Substance C is polar covalent because polar molecules have stronger intermolecular forces than non-polar and higher melting points.
2 atoms will bond with calcium to form Calcium Fluoride
Answer: Magnesium Mg
Explanation:
Oxidization is the process by which a substance either gains oxygen or losses electrons.
The chemical reaction of the above is denoted by,
Mg(s) + 2HCl(aq) -----> MgCl2(aq) + H2(g)
Mg went from a 0 to a +2 state which would mean that it lost electrons.
It was therefore oxidized.
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Answer: -105 kJ
Explanation:-
The balanced chemical reaction is,
The expression for enthalpy change is,
![\Delta H=\sum [n\times B.E(reactant)]-\sum [n\times B.E(product)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Csum%20%5Bn%5Ctimes%20B.E%28reactant%29%5D-%5Csum%20%5Bn%5Ctimes%20B.E%28product%29%5D)
![\Delta H=[(n_{N_2}\times B.E_{N_2})+(n_{H_2}\times B.E_{H_2}) ]-[(n_{NH_3}\times B.E_{NH_3})]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%28n_%7BN_2%7D%5Ctimes%20B.E_%7BN_2%7D%29%2B%28n_%7BH_2%7D%5Ctimes%20B.E_%7BH_2%7D%29%20%5D-%5B%28n_%7BNH_3%7D%5Ctimes%20B.E_%7BNH_3%7D%29%5D)
![\Delta H=[(n_{N_2}\times B.E_{N\equiv N})+(n_{H_2}\times B.E_{H-H}) ]-[(n_{NH_3}\times 3\times B.E_{N-H})]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%28n_%7BN_2%7D%5Ctimes%20B.E_%7BN%5Cequiv%20N%7D%29%2B%28n_%7BH_2%7D%5Ctimes%20B.E_%7BH-H%7D%29%20%5D-%5B%28n_%7BNH_3%7D%5Ctimes%203%5Ctimes%20B.E_%7BN-H%7D%29%5D)
where,
n = number of moles
Now put all the given values in this expression, we get
![\Delta H=[(1\times 945)+(3\times 432)]-[(2\times 3\times 391)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%281%5Ctimes%20945%29%2B%283%5Ctimes%20432%29%5D-%5B%282%5Ctimes%203%5Ctimes%20391%29%5D)
Therefore, the enthalpy change for this reaction is, -105 kJ
