Answer:
Explanation:
A pressure of 1 atm and a temperature of 0 °C is the old definition of STP. Under these conditions, 1 mol of a gas occupies 22.4 L.
1. Calculate the moles of hydrogen.
2. Calculate the number of molecules
The metal component of the given compound, CrCl3, is chromium. The number of moles per 1 g of chromium is calculated through the equation below,
n = (1 g Cr)(1 mol Cr/51.996 g Cr)
n = 0.0192 mol Cr(3 electrons/1 mol Cr)
n = 0.0577 e-
Determine the number in charge by multiplying with Faraday's constant,
C = (0.0577 mol Cr)((1 F/1 mol e-)(96485 C/ 1F)
C = 5,566.87 C
Then, calculate time by dividing the charge with the current,
t = 5566.87 C/1.5 A
t = 3711.25 minutes
t = 61.84 hours
<span><em>Answer: 61.84 hours</em></span>
<span>Pre-1982 definition of STP: 37 g/mol
Post-1982 definition of STP: 38 g/mol
This problem is somewhat ambiguous because the definition of STP changed in 1982. Prior to 1982, the definition was 273.15 K at a pressure of 1 atmosphere (101325 Pascals). Since 1982, the definition is 273.15 K at a pressure of exactly 100000 Pascals). Because of those 2 different definitions, the volume of 1 mole of gas is either 22.414 Liters (pre 1982 definition), or 22.71098 liters (post 1982 definition). And finally, there's entirely too many text books out there that still use the 35 year obsolete definition. So let's solve this problem using both definitions and you need to pick the correct answer for the text book you're using.
First, determine how many moles of gas you have. Just simply divide the volume you have by the molar volume.
Pre-1982: 2.1 / 22.414 = 0.093691443 moles
Post-1982: 2.1 / 22.71098 = 0.092466287 moles
Now determine the molar mass. Simply divide the mass by the moles. So
Pre-1982: 3.5 g / 0.093691443 moles = 37.35666667 g/mol
Post-1982: 3.5 g / 0.092466287 moles = 37.85163333 g/mol
Finally, round to 2 significant figures. So
Pre-1982: 37 g/mol
Post-1982: 38 g/mol</span>
Answer:
deposition
Explanation:
Sublmation- solid transforming into a gas, skipping the liquid stage.
eveporation- a liquid transformimg into a gas
melting- a solid transforming into a liquid
deposition- the opposite of sublimation (your anwser)
