C125 Study guides, Class notes & Summaries

If we apply the HOMO and LUMO concepts in atomic orbitals, we will have HOAO (Highest Occupied Atomic Orbitals) and LUAO (Lowest Unoccupied Atomic Orbitals). What is the LUAO of Na atom? - Answer- 3p Which one is correct about the bond lengths in PCl5? Equatorial bonds are longer because they experience smaller repulsion The axial bonds are shorter because they are far away from other bonds All P-Cl bonds have the same bond length. Axial bonds are longer because they experienc...

C125 STUDY GUIDE EXAM QUESTIONS AND ANSWERS electron delocalization - Answer- Resonance structures lower the energy through.... sp3 - Answer- What is the hybridization of the central atom in H2O? yes - Answer- can both bonding and antibonding molecular orbitals have nodal planes? perpendicular to internuclear axis - Answer- sigma and pi antibonding molecular orbitals always have a nodal plane where? 2p - Answer- If we apply the HOMO and LUMO concepts in atomic orbitals, we will h...

C215 EXAM REVIEW -QUESTIONS WITH COMPLETE ANSWERS which of the following orbitals of H has the highest energy 2p 4s 1s 3d - Answers- 4s a 100-mL sample of Pb initially has a concentration of 12.3 ppm, if this sample was diluted to 400 mL, what is the new concentration in ppm - Answers- 3.1 which of the following is directly proportional to the concentration of a solution sample (a)intensity of light passing through (b)extinct coefficient (c)transmittance of light (d)absorban...

C215 EXAM-QUESTIONS WITH CORRECT ANSWERS Calculations: Corrected Gas Pressure - Answer- - Gauge pressure read (Psig) must be corrected to include the atmospheric pressure (Psia) asserted on the gauge - P corrected = Gauge Pressure Read (Psig) + Atmospheric Pressure (Psia) Acids - Answer- - Substances that produce H+ in solution Bases - Answer- - Substances that produce OH- in solution Acid-Base Reaction (Neutralization Reaction) - Answer- - Acid & base neutralize each other proper...

C215 PRACTICE EXAM QUESTIONS AND ANSWERS A company manufactures and distributes its own products. When should the company consider outsourcing its distribution? When the company can no longer accurately forecast its transportation costs When the company's distribution costs are the lowest in the industry When the company determines that distribution is no longer a core function When new federal regulations give the company a competitive advantage - AnswerWhen the compa...

C215 STUDY NOTES EXAM QUESTIONS WITH CORRECT ANSWERS an element (often a metal or reactive gas) displaces another element from a compound E + AB ----> EB + A -Answer- single displacement reaction an exchange of elements takes place between two compounds AX + BY ----> AY + BX -Answer- double displacement/metathesis reaction four driving forces of displacement reactions -Answer- formation of a precipitate formation of gas formation of water formation of a soluble weak electr...

CHEM C125 MIDTERM EXAM QUESTIONS WITH CORRECT ANSWERS

CHEM-C125 ASSESSMENT TEST QUESTIONS WITH CORRECT ANSWERS A solid sample contains both NaOH and NaCl. 0.500 g of this solid sample was dissolved in water to make a 20.0 mL solution and then this solution was titrated by 0.500 mol/L HCl solution. If 22.5 mL of HCl was used to reach the end point, what is the mass % of NaOH in the original solid sample? NaOH + HCl --> NaCl + H2O - Answer- 90 During titration, it is very common to have some NaOH spilled to the inside wall of Erlenmeyer fl...

CHEM-C125 EXAM #3 QUESTIONS WITH CORRECT ANSWERS ten-fold difference in concentration of conjugate pairs - Answer- any pH change of 1 unit is a ... the choice of the system and thus the Ka. the ratio of the concentration of conjugate pairs. - Answer- what does the pH of a buffer depend upon? added strong acid or added strong base - Answer- buffering capacity: has the ability to absorb... need to prepare a buffer solution with a specific pH; assume [base] = [acid] - Answer- how to ch...

Aliquot - Answer- - *Portion of measurement added* - Example: "In this experiment, we will be using an *aliquot* of 10 mL of water for each trial Sig Fig Rules (Significant) - Answer- - Any non-zero digit is a sig fig - Zeros between non-zeros are sig figs - Zeros to the right of the last non-zero digit are sig figs Sig Fig Rules (Insignificant) - Answer- - Zeros to the left of the first non-zero are NOT sig figs Calculations Rules for Sig Figs (+/-) - Answer- - Focus on decim...