A volumetric calcium analysis on triplicate samples of the blood serum of a patient believed to be suffering from a hyperparathyroid condition produced the following data: mmol Ca/L = 3.15, 3.25, 3.26. What is the 95% confidence interval for the mean of the data, assuming no prior information about the precision of the analysis?

agine. [15-7:1] 36 kJ/kg mol K , diatomics = 20-9 kJ/kg mol K. Air contains 21% oxygen by volume. 18. The volumetric analysis of a gas is as follows: CO 30%, H, 60% CH4 10%. This gas is mixed with air in the proportions 1 volume of gas [(a) 21-8 (b) 1-21 kg/m³; (c) 1-39; (d) 0-381 kJ/kg K] Take the molar specific heat capacities at constant volume for: CH, = (b) the density of the mixture in kg/m³ at 27°C and 138 kN/m23; to 1-5 volumes of air. Determine, for the air-gas mixture: (a) the mean relative molecular mass of the mixture; (c) the value of the adiabatic index for the mixture; (d) the characteristic gas constant for the mixture. 7. الممسوحة ضوئیا ب CamScanner QUESTIONS 647 Find the composition hy mn0 10

An environmental chemist working for the Environmental Protection Agency (EPA) was directed to collect razor clams from a heavily-contaminated river superfund site and analyze them for their Cd²+ content using graphite furnace atomic absorption spectrometry (GFAAS). The chemist dried the clams at 95 °℃ overnight and ground them in a scientific blender, resulting in approximately 50 g of homogenized dry weight. A representative 73.69 mg sample was taken from the approximately 50 g of dry material and dissolved in 100.0 mL of 0.1 M HCl to create a sample solution. Using the method of standard additions, the chemist prepared five standard solutions in 100.0 mL volumetric flasks, each containing 5.00 mL aliquots of the sample solution. Varying amounts of a 84.0 ppb (µg/L) Cd²+ standard were added to each of the flasks, which were then brought to volume with 0.1 M HCl. The Cd²+ content of the solutions was then analyzed using GFAAS, resulting in the absorbance data given in the table.…

Given: Trial 1 25.00 0.00 10.40 10.40 Trial 2 25.0 10.40 20.13 9.73 Volume of Ca(OH)2 (mL) Initial burette reading (mL) Final burette reading (mL) Volume of HCl used in titration (mL) answer in 3 significant figures. Trial 3 25.0 20.13 30.29 (a) write the neutralization reaction involved in the experiment. (b) Calculate the molarity of Ca2+ (M). Show the complete solution. 10.16

You are required to prepare 5 L of a solution containing 1.000 x 103 mol/L of Cu2"(aq). Which of the following procedures would produce an appropriate solution? O Dissolve 0.0636 g of copper metal in nitric acid, add to a 5.000 Lvolumetric flask, dilute to the mark with deionized water and mix well. O Dissolve 1.248 g of CuSO.5H,0(s) in deionized water, add to a 5.000 L volumetric flask, dilute to the mark with deionized water and mix well. Dissolve 0.250 g of CUSO,.5H,O(s) in deionized water, add to a 5.000 L volumetric flask, dilute to the mark with deionized water and mix well.

32x882 2715028=62±3272 Rb K Ba Ca Na Mg AI Mn Zn Cr Co Sn H₂ Cu Ag Hg Reference: Activity Series react with cold water and acids, replacing hydrogen react with acids or steam, but usually not liquid water, to replace hydrogen react with acids, but not water, to replace hydrogen ***reference point*** react with O to form oxides mostly unreactive Increasing Reactivity

Analysis of a standard solution at a concentration of 5 ppm Fe (III) is done with a new analysis method. The experiment is repeated 3 times, and the average iron ion concentration is determined as 4.7 ppm. The standard deviation, s = 0.1, is calculated according to the results of the three experiments. Does the new analysis method contain systematic errors at a 95% confidence level? (Choose the t value from the Table) t values Degrees of freedom 95% CL 1 12.7 4.3 3.18 4 2.78 O a. A systematic error exists O b. Only random error exists

Find the volume in liters of carbon dioxide gas (CO2) produced at 1.00 atm pressure and 25.0 ∘C from 5.37 mL of 1.00 M HNO3(aq) solution with an excess of sodium carbonate (Na2CO3) according to the unbalanced reactionHNO3(aq) + Na2CO3(aq) → NaNO3(aq) + H2O(l) + CO2(g) Give the answer with 3 or more significant figures.

The great French chemist Antoine Lavoisier discovered the Law of Conservation of Mass in part by doing a famous experiment in 1775. In this experiment Lavoisier found that mercury(II) oxide, when heated, decomposed into liquid mercury and an invisible and previously unknown substance: oxygen gas. 1. Write a balanced chemical equation, including physical state symbols, for the D-0 decomposition of solid mercury(II) oxide (HgO) into liquid mercury and gaseous dioxygen. 2. Suppose 54.0 mL of dioxygen gas are produced by this reaction, at a temperature of 50.0 °C and pressure of exactly 1 atm. Calculate the mass of mercury(II) oxide that must have reacted. Round your answer to 3 significant digits. APR 24 MacBook Air

a dilution is needed to prepare a standard of 10 mg Zn/L from 0.5g Zn/L. To carry out the dilution we have the following available bulb pipettes: 1ml,2ml,5ml,10ml,20ml and 25 ml and the following volumetric flask: 50ml,100ml,250ml,500ml. which bulb pipette and which corresponding volumetric flask you would choose to carry out the dilution?