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

Suppose the absorbance of a 0.084 M solution of nickel(II) nitrate in water is measured to be 0.305 in a cuvette with a path length of 1.00 cm. If the solution is then diluted by a factor of 3, what do you expect the absorbance of the diluted solution to be, when measured in the same 1.00-cm cuvette? Round your answer to the correct number of significant figures

A) Standard solution and Beer's law calibration curve 1-Fill in the following table : Concentration For S.1 M¸ x V = Ma x V 0.000725 x 1.0ml Ma x 10.0ml Solution Absorbance Concentration S. 1 8.2 S 3 S 4 ASA of unknown ????????? 2- Plot a graph of Absorbance vs. conc mol /L

An aqueous solution was created by placing 0.018 g of NaCl into a 50 mL volumetric flask and diluting to volume with deionized water. (Because the amount of solute is small, you may assume that the volume & density of the solution is equal to the volume & density of the solvent where appropriate.) Find the concentration in terms of the following units.  Report your answers without scientific notation. Only input numbers. Your answers must be expressed to the correct number of significant figures. Any values less than one must have a zero in front of the decimal (e.g. 0.01 not .01) Molarity: M Molality: m Mole Fraction of NaCl (X): Mass % of NaCl: %

11 of 11 I Review | Constants Periodic Table Suppose that you want to find the equation for a line that passes through the two points (0,3) and (4, 9). What is the slope of this line? Express your answer numerically. > View Available Hint(s) Πνα ΑΣΦ ? m = Submit rt C Complete previous part(s) 9:41 PM 36%

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i OWLV2 | On x O Significant x 4. Access Den x G Google * Settings My Home nment/takeCovalentActivity.do?locator3Dassignment-take [Review Topics] [References] Use the References to access important values if needed for this question. A dime has a mass of 2.30 x 10¬3 kilograms and a volume of 0.390 milliliters. a. Using unit analysis, calculate the density of the dime in units of grams/milliliter. Use one of the following to set up the conversion factor. 1 kg=1000 g 1000 mL=1 L 100 cm=1 m 1000 mg=1 g 1 mL=1 cm³ 1000 mm=1m 2.30 x 10 kg (number)(unit) g/mL 0.390 mL (number)(unit) b. Based on your calculation will the dime float or sink in water? Submit Answer Retry Entire Group 9 more group attempts remaining

The standard solution is prepared by dissolving a known mass of zinc pellets with conc. HCl. The solution is then neutralized, transferred into a 250 mL volumetric flask and filled to the calibration mark. If 0.9809 g of Zn was weighed using an electronic balance with a relative uncertainty of ± 0.01 % and the 250 mL volumetric flask has a known relative uncertainty of ± 0.06 %, what would be the absolute uncertainty of the concentration of the solution? The molecular weight of the zinc pellets is 65.39 g/mol

1. Several students performed this experiment without paying adequate attention to the details of the procedure. Briefly explain what effect each of the following procedural hanges would have on the size of the volume- to- temperature ratio calculated by the students. (a) One student failed to replenish the boiling water in the boiling- water bath as the flask was being heated. At the end of the 6 min of heating, the boiling water in the bath was only in contact with the lower portion of the flask. (b) Following the proper heating of the flask in the boiling water, a student removed the flask from the boiling- water bath but only partially immersed the flask in the ice-water bath during the cooling period. (c) A student neglected to close the pinch clamp before removing the flask from the boiling water bath and immersing it in the ice-water bath. (d) One student neglected to measure the volume of the flask before leaving the laboratory. Because the procedure called for a 125-mL…