Lab 02

Explain your rationale for using the summative assessment (below) from the lesson plan on mixing substances in a 5th-grade classroom based on the below standard and learning objective, including how it aligns with the learning objective.  Summative Assessment  Summative: Components of the Lab Report Purpose: The student should clearly state the purpose of the experiment, which is to determine whether the mixing of two or more substances results in new substances. Procedure: The student should describe the steps they took to conduct the experiment. This includes the substances they chose to mix and the safety equipment they used. Observations: The student should record any observable changes that occurred when the substances were mixed. This could include a color change, the formation of a precipitate, or a change in temperature. Conclusion: The student should state whether a new substance was formed based on their observations. They should also reflect on their accuracy in…

How many of the following should be included in a good hypothesis? (1) A prediction of the results of the experiment (ii) A step-by-step walkthrough of how to do the experiment with specific references to amounts of reactants, glassware used, and other experimental details (iii) A summation of the data collected after doing the experiment, with comments on accuracy and precision if possible. (iv) A detailed list of chemicals that will be used (vi) A brief scientific explanation of the predicted results. Said another way, the hypothesis should include a scientific explanation of why the predicted results are expected. (v) Waste disposal procedures 0 1 O 2 O 3 0 4 0 5

What are replicates in Analytical Chemistry? O The component of a sample that repeats over different assays. Similar assays done to different samples A sample that contains exactly the same amount of analytes than the original sample similar samples that are analyzed at the same time and in the same way

How is accuracy and precision related to errors incurred in the chemical analysis? Why systematic errors are also called determinate errors? Why random errors are also called indeterminate errors? Give two examples of each of the following sources of errors.             a. Instrumental error             b. Personal error             c. Method/operational error

There are three types of error in the laboratory: random error, systematic error, and gross error. Elaborate how can you use standard deviation and percent error in identifying the errors made in the measurement.

Please help with questions 2-3

42.How many of the following should be included in a good hypothesis? (i) A prediction of the results of the experiment (ii) A step-by-step walkthrough of how to do the experiment with specific references to amounts of reactants, glassware used, and other experimental details (iii) A summation of the data collected after doing the experiment, with comments on accuracy and precision if possible. (iv) A detailed list of chemicals that will be used (v) Waste disposal procedures (vi) A brief scientific explanation of the predicted results. Said another way, the hypothesis should include a scientific explanation of why the predicted results are expected.   A. 1   B. 2   C. 3   D. 4   E. 5

Conservation of mass was discussed in the background. Describe how conservation of mass (actual, not theoretical) could be checked in the experiment performed.

3) For the results, discuss the significance of the following in terms of accuracy or precision: a) Deviation vs Absolute Error. b) % Error vs Standard Deviation.

How do I solve for the percent value? The sample data calculated the answers but I have no idea how they obtained the percent error values. Calculate sample data #1 with detailed steps.

Which statement is true?   Question 12 options:    Precision is measured by standard deviation.   Precision is measured by error or relative error.   Accuracy is measured by the standard deviation.

Cite possible sources of error in an experiment.

All boxes please. Answer choices: analytical technique or purpose

Please answer.

What were the main results found in this experiment? Include both quantitative results (i.e. important calculated values, including percent error) and qualitative results (i.e. important properties that were investigated).

You are trying to determine average experimental value with relative uncertainty for the volume of water measured in a 100 mL volumetric pipet with 0.08 mL precision. You follow the procedure below: 1. Weigh a 200 ml flask with a stopper on the analytical balance. Add 100 mL of distilled water measured carefully with a volumetric pipet and re- weight the flask and stopper with the water. 2. Empty the water from the flask and repeat the above procedure two more times for a total of three measurements for the pipet. You collect the following data in your lab notebook: In Lab Data Analytic Balance: Max weight 400 0.0007 g Volumetric Pipet: 100±0.08 ml Density water 1.000 g/ml Trial 1 2 3 Measured Volume (ml) 100.00 100.00 100.00 What is the average percent error in the volumes measured by the pipet? Notes: Canvas will not accept units, so please just input your value-with the correct sig fig Type your answer... Measured Mass (g) 98.1411 98.2413 98.9825

FINAL Experiment 1- January 2021_-789644623 - Saved Layout Review View Table A friend of yours went panning for gold last weekend and found a nugget that appears to be gold. With your newfound scientific prowess, you set out to determine if it is really gold. Your tests show that the nugget has a mass of 7.6 g. Immersing the nugget in water raised the volume from 7.22 mL to 8.06 mL. The density of gold is 19.32 g/cm3. What will you tell your friend? acer

Errors of different varieties may arise throughout the course of an experiment. Below, match the different types of errors with their corresponding definitions. Group of answer choices Errors that have an equal chance to be positive or negative. These errors will arise because it is impossible to make any measurement completely exact. Errors that will have a consistent directional bias every time the experiment is carried out. These errors tend to always be positive or negative, meaning over or underestimating, respectively, the true value of the measurement due to experimental limitations. An error that is within the direct control and/or caused by a mistake from the chemist. Options Random error Systematic error Human mistake

Determine the Average Mass and the Standard Deviation for the following data: Mass of pennies in grams = 1.5021, 1.4736, 1.4966, 1.5164, 1.5420, 1.4699 g. Average Mass grams +/- Standard Deviation grams

The gold content of an ore is being measured. The results of these analyses are:  Content (ppt) 20.065 19.999 21.054 20.533 20.088 20.112 What is the average value, standard deviation and confidence interval for this set of data?Show each step of the calculation. Using your results calculate the %accuracy and %precision (relative standard deviation) if the true value is 20.045%.

Analytical Chemistry