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When wet air and dry air is put in 2 seperate beakers with a blackened brass discs which re-emits visible light absorbed in the form of infrared radiation and I shine a lamp for 10 minutes the temperature is almost the same in both the beakers. Could you please explain why?

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Keith LeannonLv2

13 Dec 2019

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12. A sample of water and a sample of ethanol are 16. A 025 M aqueous both boiling in open containers at standard pressure. For the vapor pressure(P) and temperature (T), the two liquids have are 16. AMus solution of KCI is tdfo conductivisy using the type of apparaus sh (A) the same P and the same T (B) the same P but different T (C) different Pe but the same T (D) different P and different T What do you peedisct will happen Bulb 13. Under conditions of fixed temperature amount of gas, Boyle's law requires that and 11. PV=constant (A) The bulb will noa lighn up. KCI is nonelectrolyte. (A) I only (C) III only (E) another combination (B) The bulb will not light up. KCI is in the molecular form when dissolved in water (C) The bulb will shine dimply. KCI is only partially ionized in aqueous solution. (D) The bulb will shine brightly. KCI is highly (B) II only (D) L, II, and I11 14. W ionized in aqueous solution. hat is the minimum amount of time that you should wash your eyes out if they have been splashed with a hazardous chemical? 17, when the molecules of ethanol. CHOH. are added to water, the ethanol molecules (A) nonpolar; are attracted to the mopolar water (B) polar, form hydrogen boods with the polar (A) 5 minutes (C) 15 minutes (B) 10 minutes (D) 20 minutes molecules. water molecules. (C) polar, form covalent bonds with the polar water 15. When an emergency occurs (A) report the nature and location to your instructor (B) evacuate at once without notifying anyone (C) telephone friends in other labs (D) move injured person (E) open all doors as you evacuate (D) nonpolar: are not attracted to the polar water molecules. 18. Why are no unauthorized experiments allowed in the lab? (A) the student lacks laboratory experience (B) most professors love to only see their selected experiments performed (C) the stockroom may not have the reagents or (D) it may take more time to perform than expected (E) all of the above chemicals needed 19. How many liters are there in a cubic centimeter (D) 10 (C) 10 (B) 10 (A) 10

Please give me Post lab questions 2 and 3 at the bottom.

Experiment 7 - Molar Mass of a Volatile Liquid

Introduction. Given the mass of vapor at conditions of known pressure, volume, and temperature, one can determine the molar mass of the vapor. The Ideal Gas Law mathematically relates the quantities of pressure (P in atm), volume (V in liters), and temperature (T in Kelvin) and the quantity of gas (n in moles). Using the expression PV=nRT where R equals the Ideal Gas Constant 0.0821 L*atm/K*mol, one can determine the quantity of gas under given conditions of pressure, volume and temperature. The number of moles of gas is found by

n =

Because the molar mass (MM) is defined as the mass of one mole of substance in units of g/mol, the molar mass of the vapor can be determined by

MM= mass of vapor in grams/moles of vapor

In this experiment, an unknown volatile liquid is heated in a boiling water bath and is vaporized. The vapor forces air from the flask until the pressure within the flask equals the barometric pressure of the lab. As with all gases, the vapor occupies the entire volume of its container. The temperature of the vapor equals the temperature of the boiling water bath. After 8-10 minutes, the vapor is cooled. The mass of the condensed liquid is determined and the molar mass is calculated as described above.

Notes:

Check out unknown from stockroom

Record unknown number

Before weighing your condensed vapor, thoroughly dry the outside of the flask and make sure that no water is trapped under the foil cover

Do not rinse your flask with water between trials

Dispose of waste in appropriate container

Procedure. You will record your data and calculations in your lab notebook.

Obtain an unknown liquid and a 3 inch aluminum foil square. You will need two 600 or 800 mL beakers, and 3 or 4 boiling chips.

Add 3 or 4 boiling chips to the water in an 800 mL beaker and heat the water to the boiling point. Continue heating for 8 to 10 minutes after the water comes to a rolling boil. The temperature of the boiling water is 100.0^oC. This will be the temperature of the vapor. Convert the temperature to Kelvin and record in your lab notebook.

800 mL Beaker

250 mL Flask

11.

Chemical Molar Mass

1-chlorobutane 92.6 g/mol

t-butyl chloride 92.5 g/mol

trichloroethylene 131 g/mol

2-propanol 60.1 g/mol

Ethyl acetate 88.1 g/mol

n-hexane 86.2 g/mol

cyclohexane 84.2 g/mol

2-butanone 72.1 g/mol

Post Lab Questions: Answer the following questions using complete sentences. Include them after your conclusion.

1. If a lab group did not keep the flask submerged in boiling water for a full ten minutes, and some unknown never vaporized, how would that affect the calculated molar mass? In other words, would it make the calculated value too high or too low? Explain why.

2. While performing this experiment, ten lab groups have ten different unknown volatile liquids with a range of molar masses. If all lab groups have exactly the same size of flask (255 mL), and all groups took their unknown vapor to the same temperature (100.0^oC) and pressure (760.0 mmHg), how would the number of molecules within the different flasks compare? Would it vary with molar mass? How? Explain.

3. A student has determined that an unknown liquid is either 1-chlorobutane or t-butyl chloride. What other physical property(s) could be used to determine the identity of the unknown?

This is the only info I get