A-Class Visual Design

Steel Developing Tank

Chemistry - Gas Law Problems. Thanks in advance!!!?

These are a few problems I have. Please just tell me what law to use and what number is what. Thanks!

1. A stainless steel tank has a volume of 25 L. When the tank held 15.4 moles of helium, the pressure of the gas was 755 torr. The tank developed a small leak and lost 4.2 moles of gas. If the temperature remained unchanged, what was the pressure in the tank after the loss?

2. What is the volume of H2 gas requred to produce 7.53 liters of ammonia gas (NH3) at STP?
N2 + 3H2 --> 2NH3

3. The pessure of the air in an automobile tire was 32 lbs/in^2 when the tire was cool (20 degrees Celsius). After being driven for a while, the tire pressure was 38 lbs/in^2 . If the volume of the tire stays constant and no leaks develop, what is temperature of the air in the tire after driving?

4. 138 grams of Carbon Disulfide (CS2) vapors at STP were allowed to expand into an empty 50.0 L tank. After being moved to a location in the sun, the pressure was 1.14 atm. What is the temperature?

Lancenigo di Villorba (TV), Italy

TROUBLE 1)
Since you refer to Ideal Gas as Helium it is, I apply the "Ideal Gas law"

(p1 * V1) / (n1 * T1) = (p2 * V2) / (n2 * T2)

The experiment interests a "Throttle's Flow" of a gas from its vessel. The Temperature and the Volume remain unchanged, hence I may state

p1 / n1 = p2 / n2

retrieving

p2 = n2 * p1 / n1 = (15.4 - 4.2 ) * 755 / 15.4 = 549 torr

TROUBLE 2)
The experiment interests "Ammonia Synthesis"

N2(g) + 3 H2(g) <---> 2 NH3(g)

starting from its chemical elements. When I refer to Standard Temperature/Pressure Conditions (e.g. 0°C and 1 atm), I understand that 7.53 STP-liter of Ammonia require

3 * 7.53 / 2 = 11.29 STP-liter

11.29 liter of Hydrogen.

TROUBLE 3)
Since you refer to Ideal Gas as Air may behave, I apply the "Ideal Gas law"

(p1 * V1) / (n1 * T1) = (p2 * V2) / (n2 * T2)

The experiment interests an "Isochoric Charles law" of a gas in its vessel. The Volume remain unchanged, hence I may state

p1 / T1 = p2 / T2

retrieving

T2 = T1 * p2 / p1 = 293.16 * 38 / 32 = 345 K = 75 °C

TROUBLE 4)
Since you refer to Ideal Gas as Carbon Sulphide may behave, I apply the "Ideal Gas law"

p1 * V1 = n1 * R * T1

in order to detemine the volume occupied by CS2's 138 g in the Standard Temperature/Pressure Conditions (273.16K and 1 atm), that is

V1 = n1 * R * T1 / p1 = (138 / 76) * 0.0821 * 273.16 / 1 =
= 40.7 STP-liter

The experiment interests an "Polytropic Phenomenon" as Gas-Expansion in a greater vessel, hence I rearrange the "Ideal Gas law" in this manner

(p1 * V1) / T1 = (p2 * V2) / T2

retrieving

T2 = (T1 * p2 * V2) / (p1 * V1) =
= (273.16 * 1.14 * 50) / (1 * 40.7) = 382 K = 108 °C

I hope this helps you.

How to load 35mm Film into Development Tank

Tags:   darkroom · ebay_selling · photography · processing · stainless steel developing tank · stainless steel developing tank 35mm · steel developing tankNo Comments