posted by John b .
Write the balance equation and the reaction type when magnesium is added to HCl
2HCl + Mg ==> MgCl2 + H2
Looks like a single replacement reaction to me. Mg replaced H2.
When a covalent bond is formed between 1 mole of atoms A and 1 mole of atoms B, the overall energy of these atoms decreases and heat is released into the surroundings.
i. Is the process of a covalent bond formation exothermic or endothermic?
ii Is the change of enthalpy for the formation at constant pressure of a mole of covalent bonds between A and B positive or negative? Why?