The analyst would use an analytical balance during sample analysis, what would you recommend her/him to do before using the said instrument?

A student dissolves a Jefferson nickel to make 100.00 mL of solution in a volumetric flask. The student takes a 5.00 mL aliquot of the first solution and dilutes it to make 100.00 mL of a second solution. The student places a sample of the second solution in a cuvette for analysis using spectrophotometry. The molarity of the copper solution in the cuvette was determined by spectrophotometric analysis to be 2.90 x 10-2 M Cu. Calculate the mass of copper in the Jefferson nickel used to make the first solution. Use the diagram to help visualize the dilution process. WE IN GOD TRUST 100 mL LIBERTY 200 5 mL 100 mL cuvette

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…

The following volumes of 0.000300 M SCN are diluted to 15.00 mL. Determine the concentration of SCN in each sample after dilution. These values will be used during the experiment. To enter exponential values, use the format 1.0e-5. Sample 0.000300 M SCN (mL) [SCN'] (M) 1 1.50 3.50 7.00 4 10.00 3.

A student reacts 1.53 kg of magnesium metal with excess titanium(III) chloride solution. After the reaction was complete, the student had extracted 1.62 kg of titanium metal. From this data, calculate the percent error of this experiment.

If a water sample has 0.07 mol of calcium ions in 15 L solution, what is the water hardness level in mg/L? Pay attention to the unit. Hint: For the calcium mass , convert mol to g to mg. (1 mol calcium ion= 40.08 g/mol and 1 g = 1000 mg) Round and report your answer to an integer without decimal place. Report numeric value only, no unit. • Water hardness levels according to EPA Soft: 0-60 milligrams per liter (mg/L) as calcium carbonate Moderately hard: 61-120 mg/L as calcium carbonate • Hard: 121-180 mg/L as calcium carbonate Very hard: more than 180 mg/L as calcium carbonate

NEED A HELP WITH THIS QUESTION 06

For the Shaefer-Fulton endospore stain method, the working solution of safranin is made by combining 10 mL of stock solution with 90 mL of distilled water. If you need to produce 1,046 mL of working solution, how many grams of safranin O will be required to make the smallest batch of stock solution possible? • Report your answer in grams using standard decimal notation rounded to two decimal places. • Include trailing zeros. • Do not include the units in your answer 。 If your answer is 100.105 g it would be reported as 100.11 。 If your answers was 100.203 g it would be reported as 100.20

I am struggling with how to set this up using this conversion format.

Why is it inappropriate to report yields with decimal-place accuracy (as opposed to whole numbers)?