Functions of the skin other than thermoregulation

Methanol, ethanol, and n−propanol are three common alcohols. When 1.00 g of each of these alcohols is burned in air, heat is lib

KengaRu [80]

Answer:

For methanol: Heat of combustion = -22.6 kJ / 0.0312 moles = -724.3590 kJ/mol (negative sign signifies release of heat)

For ethanol: Heat of combustion = -29.7 kJ / 0.0217 moles = -1368.6636 kJ/mol (negative sign signifies release of heat)

For propanol: Heat of combustion = -33.4 kJ / 0.0166 moles = -2012.0482 kJ/mol (negative sign signifies release of heat)

Explanation:

Given:

Mass of Methanol = 1.0 g

Mass of ethanol = 1.00 g

Mass of n-propanol = 1.00 g

For methanol:

2 CH₃OH + 3 O₂ ----> 2 CO₂ + 4 H₂O, ∆H₀ = -22.6 kJ/g (negative sign signifies release of heat)

1 g of methanol on combustion gives 22.6 kJ of energy

Calculation of moles of methanol:

$moles=\frac{Mass(m)}{Molar\ mass (M)}$

Molar mass of methanol = 32.04 g/mol

Thus moles of methanol = 1 g/ (32.04 g/mol) = 0.0312 moles

Hence energy in kJ/mol:

Heat of combustion = -22.6 kJ / 0.0312 moles = -724.3590 kJ/mol (negative sign signifies release of heat)

For ethanol:

C₂H₅OH + 3 O₂ ----> 2 CO₂ + 3 H₂O, ∆H₀ = -29.7 kJ/g (negative sign signifies release of heat)

1 g of ethanol on combustion gives 29.7 kJ of energy

Calculation of moles of ethanol:

$moles=\frac{Mass(m)}{Molar\ mass (M)}$

Molar mass of ethanol = 46.07 g/mol

Thus moles of ethanol = 1 g/ (46.07 g/mol) = 0.0217 moles

Hence energy in kJ/mol:

Heat of combustion = -29.7 kJ / 0.0217 moles = -1368.6636 kJ/mol (negative sign signifies release of heat)

For propanol:

2 C₃H₇OH + 9 O₂ ----> 6 CO₂ + 8 H₂O, ∆H₀ = -33.4 kJ/g , (negative sign signifies release of heat)

1 g of methanol on combustion gives 33.4 kJ of energy

Calculation of moles of methanol:

$moles=\frac{Mass(m)}{Molar\ mass (M)}$

Molar mass of methanol = 60.09 g/mol

Thus moles of methanol = 1 g/ (60.09 g/mol) = 0.0166 moles

Hence energy in kJ/mol:

Heat of combustion = -33.4 kJ / 0.0166 moles = -2012.0482 kJ/mol (negative sign signifies release of heat)

5 0

3 years ago

What is the splitting of the signal in the 1H NMR spectrum for the methyl protons of 1-bromo-2-methylpropane?

Arada [10]

Answer:

doublet

Explanation:

Proton MNR is used for the determination of no. of equivalents protons in a molecule

In the molecule, single NMR signal is produced for each set of protons.

Signal splitting is called spin-spin coupling and the splitting of signals depends upon the no. of neighboring proton.

The no. of signal for a proton is equal to n+1, where n is neighboring protons.

In 1-bromo-2-methylpropane, neighboring proton for both methyl protons are one. But the chemical environment of both the methyl protons are different.

Neighboring proton for methyl protons = 1

No. of signal for methyl protons = 1+1 =2

Hence, two doublets will be generated for each set of methyl protons. protons.

3 0

3 years ago

The amount of space that matter takes up is its

Masja [62]

Answer:

i think volume

Explanation:

3 0

3 years ago

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According to john dalton, elements consist of tiny particles called __________. Atoms of each element are __________ to each oth

Zepler [3.9K]

According to john dalton, elements consist of tiny particles called atoms. Atoms of each element are similar to each other. Compounds consisted of atoms of different elements combined together.

8 0

3 years ago

Which is an example of ionization? C + O2 mc004-1.jpg CO2 H2CO3 mc004-2.jpg H2O + CO2 SO2 + H2O mc004-3.jpg HSO3– + H+ Mg(OH)2 m

MrMuchimi

Your answer is SO2 + H2O ---> HSOS- + 2OH-

3 0

3 years ago

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Functions of the skin other than thermoregulation​

Functions of the skin other than thermoregulation