The bond that exist between two oxygen atoms is
called a double covalent bond. This bond involves the sharing of four electrons
to obtain a more stable structure. This type of bond is much stronger than the
single covalent bond. They are much harder to break.
A mineral ranked higher in the mohs scale is relatively harder than other minerals. Mohs scale lists 10 minerals from the softest to hardest. The hardest mineral is diamon while the softest one is talc. The two minerals compared are scratched with each other. The scratched one is the softer mineral.
It changes the chemical composition of the magnesium into something else (whitish substance)
Answer: barbiturates
Explanation: barbiturates is a kind of drug that can produce effects similar to those of alcohol, ranging from mild relaxation to an inability to feel pain, loss of consciousness, and impaired judgment.
Answer:
The enthalpy of vaporization of water at 273 K and 1 bar = 44.9 KJ/mol
Explanation:
Enthalpy of vaporization of water at 273 K, ΔHvap(T₂) is given as;
ΔHvap(T₂) = ΔHvap(T₁) + ΔCp * (T₂ - T₁)
where ΔCp = molar heat capacity of gas - molar heat capacity of liquid
Therefore, ΔCp = (33.6 - 75.3) = -41.70 J/(mol K) = 0.0417 kJ/(molK)
substituting ΔCp = 0.0417 kJ/(mol K) in the initial formula
;
ΔHvap(T) = ΔHvap(T1) + ΔCp * (T₂ - T₁)
ΔHvap(T₂)= 40.7 kJ/mol + {-0.0417 kJ/(mol K) * (272 - 373 K)}
ΔHvap(T₂) = 44.9 kJ/mol
Therefore, enthalpy of vaporization of water at 273 K and 1 bar = 44.9kJ/mol
