Question

Which of these statements is/are true? Rewrite each false statement to make it true.

Answer 1

Answer:

Explanation:

surface tension is first defined as a surface phenomenon in which it behaves like an elastic skin. Scientifically, it can be defined as the force acting perpendicular to a surface.

calculating the molar mass of CH3Br = 12 + (1*3) + 74

= 97 g/mol

molar mass of CH3Cl = 12 + (1*3) + 35.5

=50.5 g/mol

Therefore as seen above, the mass of CH3Br is greater than the mass of CH3Cl and hence this affects their individual forces as earlier stated.

Surface tension is directly proportional to the surface energy. Surface energy basically have to do with the inter-molecular bonds within the atoms of the molecule. Cohesion is defined as attracts between molecules of a fluid when creates a net force of zero and hence cause its spherical shape. Adhesive forces are simply just the attraction of molecules of the fluid and the surface which it is found.

Organic compounds (Alkanes) like wax (paraffin wax)which have low surface energy due to its non-polar functional group and its weak dipole-dipole bonds. Therefore, water adheres weakly to the wax and strongly to its molecules hence its spherical shape

Answer 2

Answer:

TRUE- The surface tension of CH3Br is greater than the surface tension of CH3Cl.

FALSE-Water forms spherical drops on wax because the surface tension of water is greater than the adhesive forces between wax and water.

Explanation:

• The statement that, the surface tension of CH3Br is greater than the surface tension of CH3Cl is true.
• This is because of the fact that CH₃Br has more molar mass compared to CH₃Cl. Additionally, CH₃Br has greater dispersion forces and is more polarizable thus having greater surface tension compared to CH₃Cl.
• The statement that "Water forms spherical drops on wax because the surface tension of water is greater than the adhesive forces between wax and water" is FALSE.
• We would correct it by saying, Water forms spherical drops on wax because the cohesive force of water is greater than the adhesive forces between wax and water.
• Cohesive forces are forces of attraction between molecules or particles of the same type while adhesive forces is a force of attraction between molecules of different type.