UNE CHEM 1011 MIDTERM Exam Questions with Correct Answers

UNE CHEM 1011 MIDTERM Exam Questions with Correct Answers Intermolecular forces - Correct Answer attractive forces that exist between molecules particles in a solid - Correct Answer tightly packed together, arranged in a regular pattern and generally DO NOT move in relation to one another particles in a liquid - Correct Answer close together with no regular arrangement; can move past each other but remain in essentially constant contact particles in a gas - Correct Answer are far apart with no regular arraneement; they move independently of one anothre except when they collide the phase which a substance exists depends on what? - Correct Answer the intermolecular forces (IMFs) and the kinetic energies of its molecules (kinetic energies is the energy rquired to overcome the attractive forces and thus increase the distance between particles) viscosity - Correct Answer a measure of a fluid's resistance to flow; can measure by the rate at which a metal ball falls through a liquid or the rate at which a liquid flows through a narrow tube water & gas that flow freely =LOW viscosity syrup & honey that don't flow freely = HIGH viscosity ** the more structurally complex the substance the molecules in a liquid, the STRONGER the IMFs between them = more difficult to move past each other =GREATER VISCOSITY how does temperature affect viscosity - Correct Answer as we increase temperature, molecules move mroe rapidly and their kinetic energies are better to overcome the forces that hold them together (can move past each other more easily) = DECREASES viscosity cohesive forces - Correct Answer intermolecular forces that bind similar molecules to one another ; the molecules WITHIN a liquid are surrounded by other molecules and are attracted EQUALLY in all directions by the cohesive forces within a liquid What causes the spherical shape in liquids - Correct Answer molecules on the surface of a liquid are attracted to half as many molecules so these unbalanced molecular