11.2 litre of hydrocarbon at NTP prdoduce 44.8 litre of CO2 and 36 gra...
**Solution:**
To find the molecular formula of the hydrocarbon, we need to determine the number of carbon and hydrogen atoms present in the compound.
**1. Calculate the number of moles of CO2:**
Given that 44.8 liters of CO2 are produced, we can use the ideal gas law to calculate the number of moles of CO2.
Using the ideal gas law equation: PV = nRT
Where,
P = pressure (at NTP, pressure = 1 atm)
V = volume (in liters)
n = number of moles
R = ideal gas constant (0.0821 L.atm/mol.K)
T = temperature (at NTP, temperature = 273 K)
Substituting the values:
1 * 44.8 = n * 0.0821 * 273
n = 1.76 moles of CO2
**2. Calculate the number of moles of H2O:**
Given that 36 grams of H2O are produced, we can calculate the number of moles of H2O using the molar mass of water.
Molar mass of H2O = 2(1.01 g/mol) + 16.00 g/mol = 18.02 g/mol
Number of moles of H2O = 36 g / 18.02 g/mol = 1.998 moles
**3. Calculate the number of moles of carbon and hydrogen:**
Since CO2 is produced from the complete combustion of the hydrocarbon, each mole of CO2 corresponds to 1 mole of carbon.
Number of moles of carbon = 1.76 moles
Since H2O is produced from the complete combustion of the hydrocarbon, each mole of H2O corresponds to 2 moles of hydrogen.
Number of moles of hydrogen = 1.998 moles * 2 = 3.996 moles
**4. Determine the empirical formula:**
To find the empirical formula, we need to determine the simplest whole number ratio of carbon to hydrogen.
Divide the number of moles of carbon and hydrogen by the smallest number of moles:
Carbon: 1.76 moles / 1.76 moles = 1
Hydrogen: 3.996 moles / 1.76 moles = 2.27
Round the ratio to the nearest whole number:
Carbon: 1
Hydrogen: 2
The empirical formula is CH2.
**5. Determine the molecular formula:**
To find the molecular formula, we need to determine the ratio between the empirical formula mass and the molar mass of the compound.
The empirical formula mass of CH2 = 12.01 g/mol + 2(1.01 g/mol) = 14.03 g/mol
The molar mass of the hydrocarbon = 14.03 g/mol
Given that 11.2 liters of the hydrocarbon at NTP are used, we can calculate the number of moles using the ideal gas law as done previously.
Number of moles = PV / RT = (1 * 11.2) / (0.0821 * 273) = 0.506 moles
To determine the molecular formula, divide the molar mass of the hydrocarbon by the empirical formula mass:
Molar mass / Empirical formula mass =
11.2 litre of hydrocarbon at NTP prdoduce 44.8 litre of CO2 and 36 gra...
Hydrocarbon is C4H8
MW=48+8=56 correct or not?
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