Now to solve this problem, we are given the number of atoms
therefore we must first convert this into number of moles. We can do this by
using the Avogadro’s number. Calculating for number of moles of Carbon:
number of moles Carbon = 21 atoms of carbon (1 mole / 6.022
x 10^23 atoms C)
number of moles Carbon = 3.49 x 10^-23 mol C
Converting this to mass by multiplying the molar mass of
C:
mass Carbon = 3.49 x 10^-23 mol C (12 g / mol)
mass Carbon = 4.18 x 10^-22 g
Therefore the mass of one molecule of Cortisone is:
mass of 1 molecule Cortisone = 4.18 x 10^-22 g / 0.6998
mass of 1 molecule Cortisone = 5.98 x 10^-22 g per molecule
Converting this to mass per 1 mol of Cortisone, by using
again the Avogadro’s number:
mass of 1 mol Cortisone = (5.98 x 10^-22 g / molecule) (<span>6.022
x 10^23 molecules / mol)</span>
mass of 1 mol Cortisone = 360.10 g / mol = molar mass of
cortisone
Answer:
360.10 g / mol
Answer:
36.5 g CO2
Explanation:
First, Write a Balanced Equation
C + 2 ZnO → CO2 + 2 Zn
Useful Information,
MW of ZnO = 81.41 g
MW of CO2 = 44.01 g
135 g ZnO x (1 mol ZnO / 81.41 g ZnO) x (1 mol CO2/2 mol ZnO) x ( 44.01 g CO2 / 1 mol CO2 ) = 36.5 g CO2
Answer:
Energy is transferred when atoms are rearranged.
Explanation:
Correct answer: 18
The outermost shell is full when that shell reaches 2(n²) electrons distributed by holding-capacity of each layer, where n is the outermost shell number. The element with an atomic number of 18 has 18 electrons around it. For the first shell, it is full when it has two electrons [2(1²)= 2 on the first shell]. The second shell is full when it has six electrons [2(2²)= 2 on the first shell + 6 on the second]. The third shell is full when it has 8 electrons [2(3²)= 2 on the first shell + 6 on the second + 8 on the third shell]. 18 electrons fill up the outermost shell of the element.
Answer:
there is 2% of hydrogen and 98% of nitrogen (mass percent)
Explanation:
assuming ideal gas behaviour
P*V=n*R*T
n= P*V/(R*T)
where P= pressure=1.02 atm , V=volume=7.47 L , T=absolute temperature= 296 K and R= ideal gas constant = 0.082 atm*L/(mole*K)
thus
n= P*V/(R*T) = 1.02 atm*7.47 L/( 296 K * 0.082 atm*L/(mole*K)) = 0.314 moles
since the number of moles is related with the mass m through the molecular weight M
n=m/M
thus denoting 1 as hydrogen and 2 as nitrogen
m₁+m₂ = mt (total mass)
m₁/M₁+m₂/M₂ = n
dividing one equation by the other and denoting mass fraction w₁= m₁/mt , w₂= m₂/mt , w₂= 1- w₁
w₁/M₁+w₂/M₂ = n/mt
w₁/M₁+(1-w₁) /M₂ = n/mt
w₁*(1/M₁- 1/M₂) + 1/M₂ = n/mt
w₁= (n/mt- 1/M₂) /(1/M₁- 1/M₂)
replacing values
w₁= (n/mt- 1/M₂) /(1/M₁- 1/M₂) = (0.314 moles/3.48 g - 1/(14 g/mole)) /(1/(1 g/mole)-1/(14 g/mole))= 0.02 (%)
and w₂= 1-w₁= 0.98 (98%)
thus there is 2% of hydrogen and 98% of nitrogen