CH 105L Exp. 2 Post Lab

CH 105L Exp. 2 Post Lab - Skidmore College Date: September...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Name: Aamani Chava Date: September 24, 2007 CH 105L / Section # 003 Instructor: Prof McCluan Directions : Type in answers below each question, using complete sentences. Adjust spacing as needed. Please use 1.5 spacing in your answers. (100 points total) 1. Explain how you were able to identify which unknown metal you were given for Part A of the experiment. In your answer, report the number of your unknown, and include quantitative evidence to support your conclusion. (10 points) The unknown identified by calculating its density and comparing it to the densities of various other metals such as aluminum, brass, copper, tin, nickel, iron, zinc, etc. By collecting the initial volume of the liquid in the graduated cylinder and the mass of the solid and then measuring the final volume after the unknown solid was submerged in the water, the density was calculated by using the ratio of mass/final volume – initial volume. The reason for subtracting the initial volume from the final was to determine the volume change that the unknown solid had caused. After doing so for the first trial, the density for the solid was calculated to be 5.89 g/mL. However this was not correct so a second trial was completed and the calculations were: initial volume = 55.8 ± 0.1mL, mass of solid = 26.211 ± 0.001g, final volume = 59.1 ± 0.1mL. The density was determined by final volume – initial volume = 3.3 ± 0.2mL and then mass/volume = 26.211/3.3 = 7.9g/mL. Although this was the density for the metal iron, the metal was actually zinc, which has a density of 7.1 g/mL. The density for the unknown solid calculated was a bit inaccurate but there were sources of error that have to be considered for the inaccuracy. 2. Discuss one potential source of error for Part A of the experiment. Explain how this error may have affected your results quantitatively . (ie. a falsely low volume may have resulted in a falsely high density because volume and density are inversely proportional) (5 points) One potential source of error for Part A was inaccuracy in measuring the
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 05/04/2008 for the course CHEM 105 taught by Professor Frye during the Spring '08 term at Skidmore.

Page1 / 4

CH 105L Exp. 2 Post Lab - Skidmore College Date: September...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online