## What is the uncertainty for a 250 mL beaker?

03. Uncertainty for Volumetric Glassware

Glassware | Volume in mL | ± Uncertainty in mL |
---|---|---|

Volumetric flasks | 50.00 100.00 250.0 | 0.05 0.08 0.10 |

Buret | 50.00 100.00 | 0.05 0.10 |

Erlenmeyer flasks | 100 250 | 5 10 |

Beaker | 50 100 | 5 5 |

## What is the uncertainty for a beaker?

Most laboratory beakers have a precision of ±5%. Thus, a 200-mL volume would have an absolute precision of ±10 mL.

**What is the uncertainty of a 400 mL beaker?**

Cards

Term Safety goggles must be worn | Definition At all times |
---|---|

Term The uncertainty of a 20 mL cylinder is | Definition +/- 0.1 mL |

Term The uncertainty of a 400 mL beaker is | Definition +/- 5 mL |

Term The uncertainty of a burette is | Definition +/- 0.01 mL |

Term The uncertainty of a thermometer is | Definition +/- 0.2 degrees C |

### How do you find the uncertainty of a measurement?

Standard measurement uncertainty (SD) divided by the absolute value of the measured quantity value. CV = SD/x or SD/mean value. Standard measurement uncertainty that is obtained using the individual standard measurement uncertainties associated with the input quantities in a measurement model.

### What is the uncertainty of a 25 mL pipette?

Titration » Burette, pipette, flask – volumetric glassware

capacity mL | pipette | flask |
---|---|---|

tolerance mL | tolerance mL | |

20 | 0.030 | |

25 | 0.030 | 0.030 |

50 | 0.050 | 0.050 |

**What is the weight of the 250 mL beaker with water?**

Metric Measurement: MASS

OBJECT | WEIGHT BEFORE | WEIGHT CHANGE |
---|---|---|

100 ml graduated cylinder | 115.65 g | 34.75 g |

250 ml beaker | 271.15 g | 145.29 g |

Chewing Gum | 4.60 g | 3. 25 g |

## What is the degree of uncertainty?

All measurements have a degree of uncertainty regardless of precision and accuracy. This is caused by two factors, the limitation of the measuring instrument (systematic error) and the skill of the experimenter making the measurements (random error).

## What is a good standard error of measurement?

A value of 0.8-0.9 is seen by providers and regulators alike as an adequate demonstration of acceptable reliability for any assessment. Of the other statistical parameters, Standard Error of Measurement (SEM) is mainly seen as useful only in determining the accuracy of a pass mark.

**What is the uncertainty for mL?**

In the graduated cylinder shown in Figure 1, the mL graduations are marked and can be read with certainty. All graduated glassware is read with one estimated digit, so this measurement is recorded correctly to the nearest 0.1 mL, with an understood uncertainty of ± 0.1 mL.