| Q. | Vapor density? | Related Search:
Chemistry | | | A compound X contains element Q. Percent by weight of element Q is 64.8%. The Vapor Density of compound X at 27 C and 750 mm Hg is 3.53 g per liter. Calculate molecular weight of compound X.
| | A. | There isn't enough information, you aren't given a second volume. | | | |
| Q. | What are possible errors for molecular mass determination by vapor density method? | Related Search:
Chemistry | | | List the most serious sources of error that could be anticipated, where possible and estimate probable effect on the final result by using the vapor density method.
| | A. | Well I am unfamiliar with the vapor density method or the experiment you must do to figure it out, but many sources of error are pouring water from one container to another will decrease volume, bubbles in water will increase volume, reading a thermometer incorrectly, spilling water, not heating or cooling a substance for long enough, mathematical errors..... Just think of really obvious but tiny details. I hope I kind of helped! | | | |
| Q. | How to find molecular formula from vapor density, pressure and temp? | Related Search:
Chemistry | | | A certain compound containing only carbon and hydrogen was found to have a vapor density of 2.550 g/L at 100°C and 760 mm Hg. If the empirical formula of this compound is CH, what is the molecular formula of this compound?
thank you very much sfyankee for your help.
| | A. | use the formula: MM = dRT/P
100°C = 373K
760 torr = 1atm
MM = (2.550g/L)(0.08206/mol*K)(373K)/(1atm)
MM = 78.05g/mol
MM CH = 13 g/mol
78.05g/mol / 13g/mol = 6
C6H6 | | | |
| Q. | A chemist vaporized a liquid compound and determined its density. If the density of the vapor at 90°C and 767? | Related Search:
Chemistry | | | A chemist vaporized a liquid compound and determined its density. If the density of the vapor at 90°C and 767 mmHg is 1.475 g/L, what is the molecular mass of the compound?
WebAssign will check your answer for the correct number of significant figures. 1 amu
| | A. | n = PV/RT = 1.0092 atm x 1.000 L / (0.082057 x 363.15 K) = 0.03387 mole
1.475 g / 0.03387 mole = 43.553 g/mol
molar mass = 43.6 g/mole (3 s.f.)
molecular mass = 44 amu | | | |
| Q. | What is the density of the ethanol vapor? | Related Search:
Physics | | | Actual question:
An industrial process can be used to change ethylene (CH2CH2) into ethanol (C2H5OH). The process uses a catalyst, high pressure (6.8MPa), and temperature of 3x10^3 degrees Kelvin. What is the density of the ethanol vapor under these conditions?
| | A. | One could use the gas laws to come up with a superficial answer to this, but it could well be wrong: under that much pressure, ethanol may well not act as an ideal gas. | | | |
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