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:
the cells in your body
Explanation:
Most people that i have asked this similar question to, have said the sun. It's not the sun because the sun disappears at night. Your body produces heat because your cells are burning up energy.
Answer:
D. 0.543kg of copper metal is produced from 0.680kg of copper 1 sulphide.
Explanation:
First write the equation for the reaction:
Cu2S + O2 ------> 2Cu + SO2
Determine the mole ratio of the two substances:
I mole of Cu2O forms 2 moles of Copper metal
The number of moles of copper 1 sulphide used is;
n = mass of Cu2S / molar mass of Cu2S
Mass = 0.680kg = 680g
Molar mass = 159.16g/mol
n = 680g / 159.16g/mol
n = 4.272moles
Determine the number of mole of copper:
Number of moles of copper metal produced from 4.272moles of copper 1 sulphide is therefore:
n of copper = 2 * 4.272 Moles
n = 8.544moles.
Determine the mass copper:
The mass of copper metal produced is therefore = number of moles of copper * molar mass of copper
mass = 8.544 moles * 63.55g/mol
mass = 542.97grams
Mass = 0.543kg
Answer:
2.2 % and 0 %
Explanation:
The equation we will be using to solve this question is:
N/N₀ = e⁻λ t
where N₀ : Number of paricles at t= 0
N= Number of particles after time t
λ= Radioactive decay constant
e= Euler´s constant
We are not given λ , but it can be determined from the half life with the equation:
λ = 0.693 / t 1/2 where t 1/2 is the half-life
Substituting our values:
λ = 0.693 / 55 s = 0.0126/s
a) For t = 5 min = 300 s
N / N₀ = e^-(0.0126/s x 300 s) = e^-3.8 = 0.022 = 2.2 %
b) For t = 1 hr = 3600 s
N / N₀ = e^-(0.0126/s x 3600 s) = 2.9 x 10 ⁻²⁰ = 0 % (For all practical purposes)
