Answer:
Percentage composition = 14.583%
Explanation:
In chemistry, the emprical formular of a compound is the simplest formular a compound can have. It shows the simplest ratio in which the elements are combined in the compound.
Percentage composition by mass of Nitrogen
Nitrogen = 14g/mol
In one mole of the compound;
Mass of Nitrogen = 1 mol * 14g/mol = 14g
Mass of compound = 1 mol * 96.0 g/mol = 96
Percentage composition of Nitrogen = (Mass of Nitrogen / Mass of compound) * 100
percentage composition = 14/96 * 100
Percentage composition = 0.14583 * 100
Percentage composition = 14.583%
Answer:
ΔH = +26.08 kJ/mol
Explanation:
The change in enthalpy (ΔH) is given in J/mol, and can be calculated for dissolution by the equation:
ΔH = m(water)*Cp*ΔT/n(solute)
The mass of water is the density multiplied by the volume
m = 1g/mL * 25.0mL = 25.0 g
The number of the moles is the mass divided by the molar mass. Knowing the molar masses of the elements:
N = 14 g/mol x 2 = 28
H = 1 g/mol x 4 = 4
O = 16 g/mol x 3 = 48
NH₄NO₃ = 80 g/mol
n = 1.25/80 = 0.015625 mol
So,
ΔH = 25*4.18*(25.8 - 21.9)/0.015625
ΔH = 26,083.2 J/mol
ΔH = +26.08 kJ/mol
Answer:
a) 0.525 mol
b) 0.525 mol
c) 0.236 mol
Explanation:
The combustion reactions (partial and total) will be:
C₇H₁₆ + (15/2)O₂ → 7CO + 8H₂O
C₇H₁₆ + 11O₂ → 7CO₂ + 8H₂O
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2C₇H₁₆ + (37/2)O₂ → 7CO + 7CO₂ + 16H₂O
It means that the reaction will form 50% of each gas.
a) 0.525 mol of CO
b) 0.525 mol of CO₂
c) The molar mass of heptane is: 7*12 g/mol of C + 16*1 g/mol of H = 100 g/mol
So, the number of moles is the mass divided by the molar mass:
n = 11.5/100 = 0.115 mol
For the stoichiometry:
2 mol of C₇H₁₆ -------------- (37/2) mol of O₂
0.115 mol of C₇H₁₆ --------- x
By a simple direct three rule:
2x = 2.1275
x = 1.064 mol of O₂
Which is the moles of oxygen that reacts, so are leftover:
1.3 - 1.064 = 0.236 mol of O₂
Answer:
Explanation:We known that Earths energy machine is driven by sunlight which acts as fuel for this machine and to strike a balance between outgoing long wave radiation and short wave radiation there are many factors which are involved in this process.Sun emits this energy in the form of short wave radiation because of the huge energy it has and short wave radiation are higher in energy.Hence, they reach the earth surface mostly as visible and UV rays.After reaching the earths surface what happens with these rays is that they get absorbed by the clouds and other constituents of Earth.
Now, this energy needs to be emitted back in to space in order to balance out the energy budget of earth and that is why this energy is emitted back as long wave radiation which have less energy and also earth has less energy unlike the sun.Loss of this energy is essential as Earth looses most of its energy through this and results in cooling.But when this OLR decreases it should be a cause of concern for us.
This imbalance is caused by a wide range of different human induced activities which has a cumulative effect on the temperature of earth.These activities gives rise to a huge gain in the CO2 concentration which is why this word has gain so much popularity and a cause of widespread concern for us.At community level we contribute to this heating by increasing usage of personal automobiles rather than going for public transport , advancement in technology has greatly changed our lifestyles making it more simpler and easier but this demands more energy consumption.Landscape changes are one of the most important because its taking place at a faster rate.Most of the land being cleared off to built new houses which means clearing off the existing vegetation which leads to temperature rise.Setting up of Industry depending on its type can reduce the amount of OLR escaping the surface by introducing more amount of GHGs in to the atmosphere.
Its these small communities which add up to become the entire human population causing a massive damage and hence at community level if people realize and take necessary steps things will start to change.
