Question

3,1Table
Compound Formula Boiling point
A. CH4. -161,6
B. C2H6. -89,0
C. C5H12. 36,2
D. C6H14. 68,7
E. C20H42. 343,0
3,1,1 Define the term boiling point
3,1,2Calculate molecular mass of compound D
3,1,3 In what phase is compound B at 25'C. Choose from gas, liquor, solid
3,1,4 Name the type of intermolecular forces in compound A
3,1,5 How does the vapour pressure of compound B compare to the vapour pressure of compound A? Write down only highthan , lower than or equal to

Consider the boiling point of compound in the table below
Substance. Boiling point
NH3. -33
H2S. -60
H2O. 100

3,2,1 Which one of the substance in table above has the weakest intermolecular forces between it's molecule.
3,2,2 Write down the type of strongest intermolecular forces found between NH3 molecules

Answer 1

3,1,1 The boiling point is the temperature at which a substance changes from a liquid to a gas at atmospheric pressure.
3,1,2 The molecular mass of compound D (C6H14) is calculated by adding up the atomic masses of all the atoms in the compound. The atomic mass of carbon (C) is 12.01 g/mol and the atomic mass of hydrogen (H) is 1.01 g/mol. Therefore, the molecular mass of compound D is (6*12.01) + (14*1.01) = 86.18 g/mol.
3,1,3 Compound B (C2H6) is in the gas phase at 25°C.
3,1,4 The intermolecular forces in compound A (CH4) are London dispersion forces.
3,1,5 The vapor pressure of compound B (C2H6) is lower than the vapor pressure of compound A (CH4).
3,2,1 H2S has the weakest intermolecular forces between its molecules.
3,2,2 The type of strongest intermolecular forces found between NH3 molecules is hydrogen bonding.