Half-life refers to the time taken for half of the atoms in a radioactive substance to decay. Therefore in 1 half-life the 80 mg of substance will reduce to 40 mg. In another half-life it will reduce from 40 mg to 20 mg, then in a third half-life from 20 mg to 10 mg. Therefore the half-life is equal to the total time taken to decay from 80 mg to 10 mg divided by 3:
t(1/2) = 36 hours / 3 = 12 hours.
Answer:
76.03 °C.
Explanation:
Equation:
C2H5OH(l) --> C2H5OH(g)
ΔHvaporization = ΔH(products) - ΔH (reactants)
= (-235.1 kJ/mol) - (-277.7 kK/mol)
= 42.6 kJ/mol.
ΔSvaporization = ΔS(products) - ΔS(reactants)
= 282.6 J/K.mol - 160.6 J/K.mol
= 122 J/K.mol
= 0.122 kJ/K.mol
Using gibbs free energy equation,
ΔG = ΔH - TΔS
ΔG = 0,
T = ΔH/ΔS
T = 42.6/0.122
= 349.18 K.
Coverting Kelvin to °C,
= 349.18 - 273.15
= 76.03 °C.
They must make sure that all things pointed out are fact, not opinion.
In a double-replacement reaction, the _____.?
There are many more interesting things to ask about double replacement reactions than are contained in the list given here. But the only correct choice is:
C.reactants are two ionic compounds
Atmospheric
pressure<span>, sometimes also called barometric pressure, is the pressure exerted by the weight of air in
the </span>atmosphere of Earth<span> (or that of another planet)</span>
1 atm is equivalent to = 101325
Pa
= 760 mmHg
= 760 torr
= 1.01325 bar
So 1.23 atm is equal to
= 124629.8 Pa
= 934.8 mmHg
= 934.8 torr
<span>= 1.2462 bar</span>
