Answer:
The new pressure is 40 atm
Explanation:
Step 1: Data given
Volume of the gas = 20.0 L
Pressure of the gas = 10.0 atm
The volume decreases to 5.0 L
Step 2: Calculate the new pressure
P1*V1 = P2*V2
⇒with P1 = the initial pressure of the gas = 10.0 atm
⇒with V1 = the initial volume of the gas = 20.0 L
⇒with P2 = the new pressure = TO BE DETERMINED
⇒with V2 = the decreased volume = 5.0 L
10.0 atm * 20.0 L = P2 * 5.0 L
P2 = 200 / 5.0
P2 = 40 atm
Since the volume is 4x smaller, the pressure is 4x more
The new pressure is 40 atm
Answer: Selectivity of mineral nutrients absorbed by roots
Explanation:
The Casparian strip in the plants are waxy coating found in the roots of the plant which helps in absorbing excess of water into the plants.
These strips thickens the walls, thus preventing the excess of soil solution from being pulled by the roots into the central part of the plant.
It helps in selecting the type and amount of nutrient into the plant but the plant having no Casparian strip will reduce the selectivity of the nutrients.
The correct answer is: 2) "argon" ; or, " Ar " ;
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→ {which is the corresponding symbol for "argon" in the "Periodic Table of Elements"}.
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Explanation:
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Note that among the answer choices provided;
Answer choice: " 3) "hydrogen sulfide" {sic} is misspelled and is supposed to be: " 3) hydrogen sulfide " .
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Note that "argon" {" Ar " } is one single element. "Argon" is one of the 6 (six) "noble gases" , which are all "monatomic" as a gas; and are:
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1) helium (He), 2) neon (Ne), 3) argon (Ar), 4) krypton (Kr), 5) xenon, and: 6) radon (Rn) .
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Let us review the other answer choice provided to see if they are incorrect:
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Choice 1) "oxygen" ; is INCORRECT. "Oxygen" exists in gaseous form as either: " O₂ " —"oxygen gas"—which is "diatomic" [has 2 (two) atoms of oxygen per molecule—and as such, NOT "monatomic" ;
or: " O₃ " — "ozone gas" —which is "triatomic" [has 3 (three) atoms of oxygen per molecule—and as such, NOT "monatomic".
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Choice 3) "hydrogen sulfide" {Note the correct spelling: "sulfide"} — is INCORRECT. "Hydrogen sulfide" ; that is: " H₂ S " — is a gaseous compound that has 2 (two) atoms of hydrogen per molecule AND 1 (one) atom of sufur per molecule—with a total of 3 (three) atoms per molecule. Thus, "hydrogen sulfide" is "triatomic" —and as such, NOT "monatomic".
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Choice 4) "Ammonia" is INCORRECT. "Ammonia" ; that is: "NH ₃ " — exists as a gaseous compound that has 1 (one) atom of nitrogen per molecule AND 3 (three) atoms of hydrogen per molecule—with a total of 4 (four) atoms per molecule. Thus, "ammonia" is "polyatomic" —more specficially, "tetratomic"—and such, NOT "monoatomic".
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Shortcut tip: We can actually rule out Choices 3 and 4 really easily because they are "compounds" (consist of more than one element), which means, at the minimum, they would be "diatomic or having an even greater number of atoms"; and as such: NOT "monatomic" .
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Hope this answer—and explanation—are of help to you!
Best wishes!
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1) Use the fact that 1 mol of gas at STP occupies 22.4 liter
=> 1 mol / 22.4 l = x / 0.125 l => x = 0.125 l * 1 mol / 22.4 l = 0.00558 mol
2) Now use the molar mass of the gas
molar mass of CO2 ≈ 44 g / mol
Formula: molar mass = mass in grams / number of moles =>
mass in grams = molar mass * number of moles = 44 g/mol * 0.00558 moles
mass = 0.246 g
Answer: 0.246 g
