Arrhenius' Law relates activation energy, Ea, rate constant, K, and temperature, T as per this equation:
K (T) = A * e ^ (-Ea / RT), where R is the universal constant of gases and A is a constant which accounts for collision frequency..
Then you can find the ration between K's at two different temperatures as:
K1 = A * e ^ (-Ea / RT1)
K2 = A* e ^(-Ea / RT2)
=> K1 / K2 = e ^ { (-Ea / RT1) - Ea / RT2) }
=> K1 / K2 = e ^ {(-Ea/ R ) *( 1 / T1 - 1 T2) }
=> K1 / K2 = e^ { (-205,000 j/mol / 8.314 j/mol*k )* ( 1 / 505K - 1/ 485K) }
=> K1 / K2 = e ^ (2.0134494) ≈ 7.5
Answer: 7.5
It is a element.
Pure substances includes either compunds, or elements. Elements are the simplest form of pure substance, they only consist of one kind of atoms. On the other hand, compounds contains two or more elements that are chemically combined together. Although you couldn't separate a compound by physical methods like filtration, but you can seperate them with chemical methods such as heating or electrolysis, using electricity.
Therefore, since compounds can be broken down eventually, so, the answer will be element.
Question:
Zinc metal is added to hydrochloric acid to generate hydrogen gas and is collected over a liquid whose vapor pressure is the same as pure water at 20.0 degrees C (18 torr). The volume of the mixture is 1.7 L and its total pressure is 0.987 atm. Determine the number of moles of hydrogen gas present in the sample.
A. 0.272 mol
B. 0.04 mol
C. 0.997 mol
D. 0.139 mol
E. 0.0681 mol
Answer:
The correct option is;
E. 0.0681 mol
Explanation:
The equation for the reaction is
Zn + HCl = H₂ + ZnCl₂
Vapor pressure of the liquid = 18 torr = 2399.803 Pa
Total pressure of gas mixture H₂ + liquid vapor = 0.987 atm
= 100007.775 Pa
Therefore, by Avogadro's law, pressure of the hydrogen gas is given by the following equation
Pressure of H₂ = 100007.775 Pa - 2399.803 Pa = 97607.972 Pa
Volume of H₂ = 1.7 L = 0.0017 m³
Temperature = 20 °C = 293.15 K
Therefore,
Therefore, the number of moles of hydrogen gas present in the sample is n ≈ 0.0681 moles.
PV = nRT
I only know the valeu of R is you're using atm, so convert kPa to atm.
1 atm = 101.325 kPa
2.52 atm = 255 kPa
2.52atm(x) = 7(.0821)(342)
2.52atm(x) = 196.5
x = 78
78 liters
It is true that the major ways people are exposed to toxins are by ingesting them, inhaling them, injecting them, or absorbing them through the skin.
<u>Explanation:</u>
Toxins can enter in four various ways into our body often referred as "route of exposure". It is one among many factors affecting toxicity.
Inhalation: When the toxin is a gas, it is usually absorbed into the body by inhalation. Inhalation of toxins may cause respiratory and lung damage. Eg: cigarette smoke
Absorption: If a toxin enters the human eye or skin, it can be absorbed into the bloodstream. This is called absorption. The skin can prevent some toxins from entering the body. For example: work stations (gas stations) where people work with toxins
Ingestion means that the person has ingested the toxin. Some chemicals cannot get into blood from digestive tract. For example: drinking contaminated water.
The injected toxin enters the body when the person carrying the toxin breaks the skin. Injections can end in veins, muscles or just under the skin. Eg: Botulinum (used to get rid of wrinkles)
In bio-chemistry, poison, a natural or synthetic substance that damages living tissue and has a harmful or lethal effect on the body, regardless of whether it is absorbed, inhaled or injected through the skin.
