Physical Sciences Exam| 560 questions| with complete solutions

Given density, what is the method to find molarity? Correct Answer: p = m/v ... solve for m ... find mol by multiplying m x mol/m (molar mass which should be given)... plug in mol into M = mol / L of solution! What are the properties of a water molecule? Correct Answer: The bent structure of the water molecule and ratio of covalently-bonded hydrogens to lone pairs of electrons on the oxygen atom maximizes the hydrogen bonding that occurs in the solid phase, producing a hexagonal structure with large empty spaces. What are the different bond angles geometry and molecular shapes to know? Correct Answer: Tetrahedral - 109 degrees, tetrahedral. Tetrahedral - 107.8 degrees, trigonal planar. Tetrahedral - 104.5 degrees, bent Trigonal planar - 120 degrees, trigonal planar Linear - 180 degrees, linear What is an extraction? Correct Answer: Way to separate a desired substance when it is mixed with others. The mixture comes in contact with a solvent, where the substance of interest is soluble but the other substances present are insoluble. Higher boiling points versus lower boiling points. Correct Answer: In distillation procedures, the component with the lower boiling point boils off first, leaving the remaining components in the original flask. How do you find formal charge? Correct Answer: Formal charge = # of valence electrons - sticks - dots Define ethanol Correct Answer: Also known as alcohol is volatile, flammable, and a colorless liquid. how do you find the maximum speed when height and mass are given? Correct Answer: KE = ½ mv2 2000 J = ½ x 10 kg x v2 4000 = 10 v2 400 = v2 20 = v What are the key kinematic equations? Correct Answer: v = vo + at Deltax = (v +vo/2) t