C125 final Study guides, Class notes & Summaries

In Atomic Spectra lab, Vernier angles (V) in degrees of a Hg-lamp has a linear dependence on wavelength (λ) in nm of line spectra: V = 0.146 λ−10.85 a) Predict the Vernier angle in degree for a line that has a wavelength of 510 nm. b) If a student found a line at a Vernier angle of 76.5°, what is the wavelength in nm of this line? - Answer- a) 63.61 b) 598.288 Best-fit line equation commonly takes "y=mx+b" format. What are y, x, m and b? - Answer- y = y-value x= x-value m = slope ...

PCl5 - Answer- All of the following molecules have all bonds being equivalent except: SF6 CH4 NH3 PCl5 lone pair to lone pair - Answer- Which of the following has the largest repulsion, assuming that all the angles between electron pairs are identical? -They are all the same because they all contain the same number of electrons -lone pair to lone pair - bonding to bonding pair -lone pair to bonding pair square planar - Answer- What is the molecular geometry of XeF4? none of ...

C125 FINAL EXAM QUESTIONS AND ANSWERS

Rearrange the following equation to solve for P. (P+a)(V-b)=nRT - Answer- P= nRT/V-b -a What is the y-intercept if B is plotted on y-axis and A is plotted on x-axis? - Answer- -20 Interpolation - Answer- estimating a value within the range of measured data extrapolation - Answer- projection; conjecture; V. extrapolate: infer (unknown information) from known information Assume that multiple trials of an experiment were performed. What is the quantity that describes how closely the re...

C125 FINAL LAB-SIMPLE EXAM QUESTIONS AND ANSWERS

The lines observed in H-lamp are parts of Balmer Series. All these lines are due to a transition from various higher n value to a common n. What is this common lower n value for all these lines? - Answer- 2 The bright violet line of Hg lamp has a wavelength of 435.8 nm. What is the energy of the photon associated with this emission line? - Answer- 4.56*10^-19 J Given: In Atomic Spectra lab, a student obtained his best-fit line equation to be y = 0.29 x + 46.8 when he plotted his Vernier re...

Rearrange the following equation to solve for V. (P+a)(V-b)=nRT - Answer- V= (nRT/P+a) +b In an experiemnt, the best-fit-line equation between Absorbance (A, unitless) and concentration (c, mg/mL) is used to calculate the concentration of Fe. Based on the best-fit line equation given below, what is the concentration of Fe if the absorbance is 1.25? A = 851 c + 0.03 - Answer- 0.0014 In y=kx + b, b is - Answer- y-intercept All of the following numbers have three sig figs EXCEPT: 1...

In Atomic Spectra lab, Vernier angles (V) in degrees of a Hg-lamp has a linear dependence on wavelength (λ) in nm of line spectra: V = 0.146 λ−10.85 a) Predict the Vernier angle in degree for a line that has a wavelength of 510 nm. b) If a student found a line at a Vernier angle of 76.5°, what is the wavelength in nm of this line? - Answer- a) 63.61 b) 598.288 Best-fit line equation commonly takes "y=mx+b" format. What are y, x, m and b? - Answer- y = y-value x= x-value m = slope ...

If you accidentally spilled some dilute HNO3 on the ground, what should you do? - Answer- Use excessive NaHCO3 to neutralize it and then clean it. Random errors may affect the... - Answer- precision but not the accuracy. Phenolphthalein is the pH indicator used in Vinegar Analysis lab. Which one of the following solutions may turn pink if a few drops of phenolphthalein is added? - Answer- 10 mL of a 0.20M HCL solution combined with 15 mL of 0.20M NaOH solution A balance always reads 0.1...