Answer:
A compound
Explanation:
A compound is a pure substance that contains atoms of more than one element.
For example, water is a compound.
It is pure because it consists only of water molecules, and each molecule contains atoms of the elements hydrogen and oxygen.
The answer is: first substance is base and second is acid.
Bases, for example solution of sodium hydroxide (NaOH) feels slipery.
Sodium hydroxide dissociation in water: NaOH(aq) → Na⁺(aq) + OH⁻(aq).
Ionic compounds are good good electricity and heat conductors, because ionic compounds have mobile ions (cations and anions) that are able to transfer electrical charge.
In second reaction, magnesium is oxidized from oxidation number 0 to +2 and hydrogen is reduced from +1 to 0 (hydrogen gas).
Answer:
CaO- ionic
InAs-covalent
Al2O3-ionic
Bronze- metallic
Explanation:
CaO and Al2O3 are mostly ionic even though the posses a little covalent character but ionic bonding is the main bonding scheme. Bronze is an alloy of two metals hence it contains a metallic bond. InAs has an electro negativity difference of 0.4 between the atoms so it is a polar covalent bond.
Below is the list of enthalpies of formation of the compounds involved in the chemical reaction.
HCl: -92.3 kJ/mol
H2: 0
Cl2: 0
Both H2 and Cl2 do not have enthaply of formation because they are pure substances.
Since, in the reaction there are 2 moles of HCl,
Enthalphy of formation = enthalpy of products - enthalphy of reactant/s
= 0 - (-92.3)(2) = +184.6 kJ
Hence, the answer is the first choice.
