C125 final lab - Study guides, Class notes & Summaries

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...

C125 FINAL LAB-SIMPLE EXAM QUESTIONS AND ANSWERS

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...

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...