Abstract Lab 6

Abstract Lab 6 - experimentation error. As the experiment...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
General Chemistry laboratory, Chem18 Experiment # 6 Date of Experiment: 11/01/2011 Date of Submission: 11/08/2011 Abstract: This lab measured the heat of reaction of two known reactions: the first was between solid magnesium and aqueous hydrochloric acid and the second was between solid magnesium oxide and aqueous hydrochloric acid. Using Hess’s Law, the heat of reactions could then be manipulated to determine the heat of formation of magnesium oxide. Based on three trials, the average heat of reaction between solid magnesium and aqueous hydrochloric acid was -481 kJ/mol and the average heat of reaction between solid magnesium oxide and aqueous hydrochloric acid was -128 kJ/mol. In correspondence with the true value of the heat of reaction, the first reaction had a relative error in accuracy of 4.14% and a relative standard deviation of -2.43%, whereas the second reaction had a relative error in accuracy of 12.3% and a relative standard deviation of -4.01%. The second reaction had a fairly major problem with accuracy, meaning that there was some sort of
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: experimentation error. As the experiment was performed in a closed thermos, the main source of error arises from the escape of heat from the thermos into the environment upon opening the thermos to add either the magnesium or the magnesium oxide (depending on the reaction). After adding the individual heats of reaction and adding them with waters literature value for heat of formation, the measured heat of formation of magnesium oxide was -639 kJ/mol compared to the true value of -602 kJ/mol. The relative error of accuracy was 6.14%, meaning the accuracy could have been better, but the measured value was not too far off from the true value. With more careful experimental procedure, the accuracy could be greatly improved. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Name Liz Zharovsky Bench C19 Lab day and section Tuesday- 2 TA Ramyaa Mathialagan Partner Siqi Liu Title: Heat of Formation...
View Full Document

This note was uploaded on 01/23/2012 for the course CHEM 18a taught by Professor Dolnik during the Fall '06 term at Brandeis.

Ask a homework question - tutors are online