gases quiz

In Parts 1 and 2, you noticed some patterns about what kind of substances conduct electricity when dissolved in water, and also how melting points are related.   Let's test this pattern by applying it to other substances. Consider the following substances: Potassium Chloride: KClKClKCl Octadecanol: C18H38OC_{18}H_{38}OC18​H38​O Dimethyl Sulfoxide: C2H6OSC_2H_6OSC2​H6​OS Lithium Bromide: LiBrLiBrLiBr Explain the reasoning that supports your answer.? Use the patterns you saw in the previous sections to predict whether the melting points for each substance will be high (above 400°C) or low (below 200°C).?

A group of students performed a melting point experiment to study the physical properties of ionic and covalent solids. The data collected are shown in the table.  Solid Sample Melting Point (oC)  Time Elapsed (min) Table Sugar (sucrose) 186 18 Table Salt (sodium chloride) 500 (not observed) 30  Paraffin Wax 37 4  Vegetable Lard 50 >5 Using the information contained in the table, what is the BEST explanation for the results?A    The melting point of sodium chloride was not observed because ionic solids do not melt, whereas sugar, wax, and lard melted because they are softer than salt.B    The melting points of covalently bonded solids tend to be lower than ionic solids. The melting point of sucrose was greater than the wax or the lard because sucrose has stronger bonds than wax or lard.C    The melting point of sodium chloride was not observed because ionic solids are composed of positive and negative ions that do not melt; whereas, the…

17.100 ml of 5:3:2 ethylene: chloroform: isoamyl alcohol 18. Convert 50 ppm to g/L 19. Convert 50 ppm to mg/L 20. Convert 5 ppb to ul/l

Posttest Direction. Read the questions carefully. Write the letter of the correct answer. 1. Water exists in three states of matter and continuously moving through a cycle on Earth. At which stage in the water cycle does water transform from a gas to a liquid? a.evaporation c. precipitation b. condensation d. Sublimation 2. Carbon dioxide (CO2) forms when coal burns in the presence of oxygen. Which of the following is the BEST evidence that a chemical reaction occurs when the coal burns? a. Production of mechanical energy c. A new substance is produced b. Production of electricity d. Formation of precipitate 3.Which of these does NOT happen during a chemical change? a. New substances are formed with different chemical properties. b. Attractive force between atoms of molecule formed or break. c. The chemical properties of the substances before and after the reaction are the same d. Energy is always released or absorbed. 4. A granular substance is added to a liquid. Which of the…

Concentration (mg/L)     Ca Mg K Na Al   50.712 68.592 9.357 11.069 12.893 Calculate the CEC for individual soil components and the total CEC for the soil. Place your    values in Table 1 below. Table 1. Ca2+ Mg2+ K+ Na+ Al3+ Total Concentration (mg/L)           -------- CEC cmol(+)/kg

1. Which of the following is not a step in preparing a water sample container?a. All sample containers must be dark in colorb. The type of sample container and the level of cleaning required depend on the type of sample to be takenc. All sample containers must be thoroughly cleaned in the laboratory before sampling is carried outd. The number of containers prepared must always be in excess of what is needed, for quality assurance, quality control and reserves 2. The purpose of environmental sample analysis is..a. To determine the origin and concentration of chemicals in the environmentb. To determine the origin, concentration of chemicals and/or pollutants in the environmentc. To determine the concentration of a chemical in the environmentd. To determine the cause and concentration of pollutants in the environment

Mass of NaCl- 2.0139g

how to separate a solid mixture of lithium bromide and barium carbonate

Dissolution Distilled H20 Concentration 0.01 M HCI Concentration (mg/ml) Time Total amount A Total amount A (mg/ml) (mg) (mg) 5 0.16 0.1 10 0.24 0.18 15 0.35 0.25 20 0.48 0.34 25 0.58 0.4 30 0.67 0.5 1. Plot the given data on an ordinary paper and find the slope for each line then calculate the IDR constant for aspirin in the two dissolution media, water and HCI. NOTE: Slope of the calibration curve = 1.0 (mg/ml and saturation solubility of salicylic acid is equal to 2.0 gm/L.

Part D: Volatiles. A 1.232 gram sample of copper complex weighed 0.783 g after heating. What is the percent of volatile material in this sample? If the sample contains 17.4% ammonia, what is the percent water in the sample?

Reagent Table Crop Reagent Amount Molecular Weight (g/mol) Molar millimoles equivalents Salcylamide 2g 137.1mg/mol 1.0 14.6mol ethanol 2.52g 149.9mg/mol 1.15 16.79mol Sodium Hypochlorite 22.88ml 74.44mg/mol 1.2 17.52mol 95% Ethanol 40ml solvent calculate theoretical yield using the chart, show calculations melting point 226celius, mass of the product 4.340 what is the percent of this?

Can you please type this out and not write it on paper, thank you!

5-10

Weigh out accurately 9.99 g of copper(II) sulfate pentahydrate (CuSO4·5H2O) by taring using a clean and dry empty 250-ml beaker. 2. Add tap water to the beaker to reach the 50-mL mark on the side of the beaker. 3. Dissolve all the crystals of CuSO4·5H2O in the water using a clean glass rod for stirring. 4. Then using a glass funnel transfer all the blue solution to a 100-mL volumetric flask. Rinse the beaker with about 10 mL of water and transfer the solution to the volumetric flask. Repeat the rinsing of the beaker with another 10 mL of water and transfer the solution to the volumetric flask. This is called quantitative transfer of the solution. 5. Then add enough water to reach the calibration mark of the volumetric flask. (You will need to use a dropper to add the last few drops of water to ensure the meniscus is on the calibration mark). Close the volumetric flask with a stopper and mix the solution well (so that it is homogeneous). 6. You have now prepared a standard solution (or…

2. Explain how suction filtration is carried out in the laboratory. Give the important points that must be observed in doing the process.

STANDARD SAMPLE PREPARATIONS FOR ABSORBANCE & CONCENTRATION DATA Concentration of stock nickel sulfate hexahydrate solution = .400 Molarity Sample Volume Absorbance Concentration (In Molarity) a 5 mL .179 10 mL .329 15 mL .588 20 mL .760 25 mL .939 Reference Blank = 0 Please show how to find Molarity, please show steps. Thank you and stay safe.