Atq Exp 1 Appendix

APPENDIX

A. Raw data

TABLE 1. Weight of Samples

Sample No. | Weight, g | | |

1 | 3.5961 | D A T A S E T 2 | D. S E T 1 |

2 | 3.5077 | | |

3 | 3.5841 | | |

4 | 3.5020 | | |

5 | 3.5994 | | |

6 | 3.5042 | | |

7 | 3.5782 | | |

8 | 3.5887 | | |

9 | 3.5939 | | |

10 | 3.5620 | | |

TABLE 2. Grubb’s Test

Data Set | Suspect Values | Qtab | Qexp | Conclusion |

1 | H: 3.5994 | 1.8871 | 1.0343 | Retain |

| L: 3.5020 | | | |

2 | H: 3.5994 | | | |

| L: 3.5020 | 2.2900 | 1.4640 | retain |

TABLE 3. Reported Values

Data Set | X | s | RSD | R | RR | CL |

1 | 3.5489 | 0.048810 | 13.754 | 0.097400 | 27.445 | 3.60013.4977 |

2 | 3.5616 | 0.040731 | 11.346 | 0.097400 | 27.347 | 3.59073.5325 |

B. Working equations and sample calculations

1. Divide the samples into Data Sets 1 and 2.

Data set 1 consists of samples 1 to 6, while data set 2 consists of samples 1 to 10.

2. Perform the Grubb’s test (at 95% confidence level) for the suspected outlier of each data set.

In data set 1, taking the absolute values of the differences of the highest and the lowest values from the mean

3.5994-3.5489=0.0505

3.5020- 3.5489=0.0469

The experimental value, g, is then calculated using the questionable measurement, the highest value (3.5994). (We use the mean computed in #3).

g= maxi=1…nXi- Xs= 3.5994-3.54890.048810= 0.05050.048810=1.0343

The suspected outlier is then compared with the tabulated critical g value.

N | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |

g95% | 1.1543 | 1.4812 | 1.7150 | 1.8871 | 2.0200 | 2.1266 | 2.2150 | 2.2900 |

g99% | 1.1547 | 1.4962 | 1.7637 | 1.9728 | 2.1391 | 2.2744 | 2.3868 | 2.4821 |

TABLE 4. Critical Values for the Grubbs Test (taken from the Analytical Chemistry Laboratory Manual)

Gtab=1.8871

Since the experimental value is less than the tabulated one, the suspected outlier should be retained.

For data set 2, taking the absolute values of the differences of the...