“Bonding molecular orbitals are formed by... in-phase combinations of atomic wave functions, and electrons in these orbitals stabilize a molecule.”
Answer:
Option C, (Actual yield ÷ percent yield) × 100
Explanation:
Theoretical yield is defined as the total amount of product formed for given reactants in a chemical reaction. It is an ideal case which assumes no exceptions or wastage.
The mathematical relation between the actual yield, percent yield and theoretical yield is as follows -
Where
P.Y. represents the percent yield a
M A.Y. represents the mass obtained from actual yield
M T.Y. represents the mass obtained from theoretical yield
Hence, if we rearrange the formula, we get -
Hence, option C is correct
Answer: Undecane, C11H24 is a liquid hydrocarbon from the alkane homologue ( family ).
Explanation:
All hydrocarbons burn in air to release H20 and CO2.
Combustion of hydrocarbons thus increases the percentage of CO2 present in the atmosphere which is not so good as CO2 is a greenhouse gas. Greenhouse gases produce the greenhouse effect. The green house effect is the warming effect produced when gases present in the atmosphere allow and retain the radiation from the sun to the earth. Examples of greenhouse gases are CO2, CH4, SO3, NO, CFCs. The greenhouse effect leads to an increase in the temperature of the earth subsequently leading to (I) melting of large amounts of ice at the poles causing flooding. (II) rapid evaporation of water from Earth’s surface. (III) decrease in crop yield.
Also, high concentration CFCs ( chlorofluorocarbons ), as widely used in aerosols, coolants and packaging foams, in the atmosphere depletes the ozone layer leading to global warming. In 1996 an international agreement was reached for a complete ban of CFCs and more countries are now going Green ( using alternative energy sources ) so as to minimize emissions of these greenhouse gases
Answer:
a=28600J; b=90.6 J/K; c=402 torr
Explanation:
(a) considering the data given
Vapour pressure P1 =0 at Temperature T1 = 42.43˚C,
Vapour pressure P2 = 273.15 at Temperature T2= 315.58 K)
Using the Clausius-Clapeyron Equation
ln (P2/P1) = (ΔH/R)(1/T2 - 1/T1)
In 760/140 = ΔH/8.314 J/mol/K × (1/315.58K -- 1/273.15K)
ΔH vap= +28.6 kJ/mol or 28600J
(b) using the Equation ΔG°=ΔH° - TΔS to solve forΔS.
Since ΔG at boiling point is zero,
ΔS =(ΔH°vap/Τb)
ΔS = 28600 J/315.58 K
= 90.6 J/K
(c) using ln (P2/P1) = (ΔH/R)(1/T2 - 1/T1)
ln P298 K/1 atm = 28600 J/8.314 J/mol/K × (1/298.15K - 1/315.58K)
P298 K = 0.529 atm
= 402 torr
