1. How does the Henry’s Law constant (KH) relate to the solubility of a gas in a liquid?
1. हेनरी के नियम नियतांक (KH) का किसी द्रव में गैस की विलेयता से क्या संबंध है?
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Detailed Explanation
The Henry’s Law constant (KH) is a constant that relates the
partial pressure of a gas above a liquid to the concentration or solubility
of that gas dissolved in the liquid at a particular temperature.
For the commonly used form of Henry’s Law:
P = KH × x
Where:
P = partial pressure of the gas above the solution
KH = Henry’s Law constant
x = mole fraction of the dissolved gas
Therefore:
P = partial pressure of the gas above the solution
KH = Henry’s Law constant
x = mole fraction of the dissolved gas
Therefore:
KH = P / x
Relation Between KH and Solubility
For the above convention of Henry’s Law, the relationship is:
Higher KH → Lower solubility of the gas
Lower KH → Higher solubility of the gas
Thus, Henry’s Law constant is inversely related to gas solubility when the equation P = KHx is used.
Higher KH → Lower solubility of the gas
Lower KH → Higher solubility of the gas
Thus, Henry’s Law constant is inversely related to gas solubility when the equation P = KHx is used.
KH ↑ → Solubility ↓
KH ↓ → Solubility ↑
KH ↓ → Solubility ↑
Why Does Higher KH Mean Lower Solubility?
From:
P = KHx
we can rearrange:
x = P / KH
At a fixed pressure, if KH increases, x decreases. Since x represents the amount of gas dissolved in the liquid, a smaller x means lower solubility.
P = KHx
we can rearrange:
x = P / KH
At a fixed pressure, if KH increases, x decreases. Since x represents the amount of gas dissolved in the liquid, a smaller x means lower solubility.
Example
Suppose two gases have the following Henry’s Law constants at the same
temperature:
Gas A: KH = 20 atm
Gas B: KH = 50 atm
At the same partial pressure, Gas A will have greater solubility because its KH value is lower.
Gas A: KH = 20 atm
Gas B: KH = 50 atm
At the same partial pressure, Gas A will have greater solubility because its KH value is lower.
Lower KH → More gas dissolves
Higher KH → Less gas dissolves
Higher KH → Less gas dissolves
Important Note About Different Conventions
Henry’s Law is written in different forms in different textbooks and
scientific sources.
For example:
P = KHx
uses KH as a pressure/mole-fraction constant, for which a higher KH means lower solubility.
Another convention may define the constant as the ratio of dissolved concentration to pressure:
C = kP
In that convention, a larger k means greater solubility.
Therefore, always check the exact equation used to define the Henry’s Law constant before comparing numerical values.
P = KHx
uses KH as a pressure/mole-fraction constant, for which a higher KH means lower solubility.
Another convention may define the constant as the ratio of dissolved concentration to pressure:
C = kP
In that convention, a larger k means greater solubility.
Therefore, always check the exact equation used to define the Henry’s Law constant before comparing numerical values.
Connection with Temperature
For most gases, increasing temperature decreases their solubility.
Therefore, under the convention:
P = KHx
the Henry’s Law constant generally increases with increasing temperature. Thus:
P = KHx
the Henry’s Law constant generally increases with increasing temperature. Thus:
Temperature ↑
→ KH ↑
→ Gas Solubility ↓
→ KH ↑
→ Gas Solubility ↓
Final Answer
For the commonly used form P = KHx, the Henry’s Law constant is
inversely related to the solubility of a gas. At a given pressure,
x = P/KH. Therefore, a larger KH means lower solubility,
whereas a smaller KH means higher solubility. The exact meaning
depends on the convention used to define KH.
विस्तृत व्याख्या
Henry’s Law Constant (KH) वह नियतांक है जो किसी द्रव में
घुली गैस की मात्रा तथा द्रव के ऊपर उपस्थित गैस के आंशिक दाब के बीच संबंध
बताता है।
Henry’s Law का एक सामान्य रूप है:
P = KH × x
जहाँ:
P = गैस का आंशिक दाब
KH = Henry’s Law constant
x = द्रव में घुली गैस का mole fraction
इससे:
P = गैस का आंशिक दाब
KH = Henry’s Law constant
x = द्रव में घुली गैस का mole fraction
इससे:
KH = P / x
KH और गैस की विलेयता का संबंध
ऊपर दिए गए Henry’s Law के convention में:
अधिक KH → कम विलेयता
कम KH → अधिक विलेयता
अर्थात P = KHx वाले convention में Henry’s Law constant गैस की विलेयता के व्युत्क्रमानुपाती होता है।
अधिक KH → कम विलेयता
कम KH → अधिक विलेयता
अर्थात P = KHx वाले convention में Henry’s Law constant गैस की विलेयता के व्युत्क्रमानुपाती होता है।
KH ↑ → विलेयता ↓
KH ↓ → विलेयता ↑
KH ↓ → विलेयता ↑
अधिक KH का अर्थ कम विलेयता क्यों?
Henry’s Law:
P = KHx
को rearrange करने पर:
x = P / KH
स्थिर दाब पर यदि KH बढ़ता है, तो x का मान कम हो जाता है। चूँकि x द्रव में घुली गैस की मात्रा को दर्शाता है, इसलिए x का कम होना गैस की कम विलेयता को दर्शाता है।
P = KHx
को rearrange करने पर:
x = P / KH
स्थिर दाब पर यदि KH बढ़ता है, तो x का मान कम हो जाता है। चूँकि x द्रव में घुली गैस की मात्रा को दर्शाता है, इसलिए x का कम होना गैस की कम विलेयता को दर्शाता है।
उदाहरण
मान लीजिए समान तापमान पर दो गैसों के Henry’s Law constants हैं:
Gas A: KH = 20 atm
Gas B: KH = 50 atm
समान partial pressure पर Gas A की विलेयता अधिक होगी क्योंकि उसका KH कम है।
Gas A: KH = 20 atm
Gas B: KH = 50 atm
समान partial pressure पर Gas A की विलेयता अधिक होगी क्योंकि उसका KH कम है।
कम KH → अधिक गैस घुलेगी
अधिक KH → कम गैस घुलेगी
अधिक KH → कम गैस घुलेगी
महत्वपूर्ण नोट: अलग-अलग Convention
अलग-अलग Chemistry textbooks और scientific sources में Henry’s Law को
अलग-अलग रूपों में लिखा जा सकता है।
एक रूप:
P = KHx
इसमें KH अधिक होने का अर्थ सामान्यतः गैस की कम विलेयता है।
दूसरा रूप:
C = kP
इस convention में k अधिक होने का अर्थ गैस की अधिक विलेयता है।
इसलिए numerical question हल करते समय यह देखना बहुत जरूरी है कि Henry’s Law constant को किस equation द्वारा define किया गया है।
एक रूप:
P = KHx
इसमें KH अधिक होने का अर्थ सामान्यतः गैस की कम विलेयता है।
दूसरा रूप:
C = kP
इस convention में k अधिक होने का अर्थ गैस की अधिक विलेयता है।
इसलिए numerical question हल करते समय यह देखना बहुत जरूरी है कि Henry’s Law constant को किस equation द्वारा define किया गया है।
तापमान से संबंध
अधिकांश गैसों की विलेयता तापमान बढ़ने पर कम होती है।
इसलिए यदि:
P = KHx
वाला convention इस्तेमाल किया जाए, तो सामान्यतः तापमान बढ़ने पर KH बढ़ता है।
P = KHx
वाला convention इस्तेमाल किया जाए, तो सामान्यतः तापमान बढ़ने पर KH बढ़ता है।
तापमान ↑
→ KH ↑
→ गैस की विलेयता ↓
→ KH ↑
→ गैस की विलेयता ↓
अंतिम उत्तर
P = KHx वाले सामान्य convention में Henry’s Law constant गैस की
विलेयता के व्युत्क्रमानुपाती होता है। स्थिर दाब पर
x = P/KH होता है। इसलिए अधिक KH का अर्थ कम गैस की
विलेयता और कम KH का अर्थ अधिक गैस की विलेयता है। हालांकि
KH की परिभाषा अलग convention में अलग हो सकती है, इसलिए
equation को देखकर ही इसका संबंध तय करना चाहिए।
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30 Related MCQs
30 संबंधित बहुविकल्पीय प्रश्न
1. Henry’s Law relates gas solubility mainly to:
A. Atomic number
B. Partial pressure
C. Neutron number
D. Density only
Answer: B. Partial pressure
2. In P = KHx, KH represents:
A. Gas concentration
B. Henry’s Law constant
C. Solvent mass
D. Temperature
Answer: B. Henry’s Law constant
3. In P = KHx, x represents:
A. Pressure
B. Mole fraction of dissolved gas
C. Temperature
D. Volume
Answer: B. Mole fraction of dissolved gas
4. From P = KHx, x is equal to:
A. P × KH
B. P/KH
C. KH/P
D. P + KH
Answer: B. P/KH
5. At constant pressure, if KH increases, solubility:
A. Increases
B. Decreases
C. Remains unchanged
D. Becomes infinite
Answer: B. Decreases
6. A gas having a smaller KH value in P = KHx form is:
A. More soluble
B. Less soluble
C. Completely insoluble
D. Always solid
Answer: A. More soluble
7. The relation between KH and x at constant P is:
A. Direct
B. Inverse
C. Exponential
D. Constant
Answer: B. Inverse
8. If KH is doubled at constant pressure, x becomes:
A. Double
B. Half
C. Four times
D. Unchanged
Answer: B. Half
9. Which gas is commonly discussed using Henry’s Law in soft drinks?
A. CO2
B. NaCl
C. CaCO3
D. HCl solid
Answer: A. CO2
10. In the convention P = KHx, high KH indicates:
A. High solubility
B. Low solubility
C. No relation
D. Infinite solubility
Answer: B. Low solubility
11. The Henry’s Law constant depends on:
A. Nature of gas and solvent
B. Temperature
C. Both A and B
D. Atomic number only
Answer: C. Both A and B
12. For most gases, increasing temperature generally:
A. Increases solubility
B. Decreases solubility
C. Has no effect
D. Converts gas to metal
Answer: B. Decreases solubility
13. Under P = KHx convention, increasing temperature generally causes KH to:
A. Increase
B. Decrease
C. Become zero
D. Remain universally constant
Answer: A. Increase
14. Henry’s Law is generally applied at:
A. Constant temperature
B. Constant atomic number
C. Constant neutron number
D. Zero pressure
Answer: A. Constant temperature
15. If KH is small, gas solubility in P = KHx form is:
A. Relatively high
B. Relatively low
C. Zero
D. Impossible to determine
Answer: A. Relatively high
16. Which equation correctly represents the commonly used mole-fraction form?
A. P = KHx
B. P = x/KH
C. x = PKH
D. P = x²
Answer: A. P = KHx
17. If P remains constant and KH decreases, x:
A. Increases
B. Decreases
C. Becomes zero
D. Remains unchanged
Answer: A. Increases
18. Which statement is correct for P = KHx?
A. KH is directly proportional to solubility
B. KH is inversely related to solubility
C. KH has no relation to solubility
D. KH is always zero
Answer: B. KH is inversely related to solubility
19. Which factor increases gas solubility at constant temperature?
A. Decreasing partial pressure
B. Increasing partial pressure
C. Increasing KH only
D. Heating always
Answer: B. Increasing partial pressure
20. The unit of KH in P = KHx depends on:
A. The pressure unit used
B. Atomic number
C. Neutron number
D. Colour of solution
Answer: A. The pressure unit used
21. Henry’s Law constant is a property of:
A. Gas-solvent system
B. Solute only
C. Container only
D. Thermometer only
Answer: A. Gas-solvent system
22. In P = KHx, if x increases at constant KH, P:
A. Increases
B. Decreases
C. Becomes zero
D. Remains unchanged
Answer: A. Increases
23. A gas with high KH in the P = KHx convention requires:
A. Higher pressure for the same dissolved concentration
B. Lower pressure for the same concentration
C. No pressure
D. Zero temperature
Answer: A. Higher pressure for the same dissolved concentration
24. Which factor can change the value of KH?
A. Temperature
B. Nature of solvent
C. Nature of gas
D. All of these
Answer: D. All of these
25. In the equation C = kP, a larger k indicates:
A. Greater gas solubility
B. Lower gas solubility
C. Zero solubility
D. No solubility
Answer: A. Greater gas solubility
26. Why must the equation defining KH be checked before comparing values?
A. Different conventions are used
B. KH is always zero
C. Pressure has no unit
D. Temperature is irrelevant
Answer: A. Different conventions are used
27. At constant pressure, x = P/KH shows that x is:
A. Directly proportional to KH
B. Inversely proportional to KH
C. Independent of KH
D. Equal to KH
Answer: B. Inversely proportional to KH
28. If Gas A has lower KH than Gas B under the same convention and temperature, Gas A is:
A. More soluble
B. Less soluble
C. Equally soluble always
D. Insoluble
Answer: A. More soluble
29. Which statement about Henry’s Law is most accurate?
A. It relates gas pressure and dissolved gas concentration
B. It relates atomic mass and pressure
C. It applies only to solids
D. It states that all gases have identical solubility
Answer: A. It relates gas pressure and dissolved gas concentration
30. In the convention P = KHx, the correct relationship is:
A. KH ↑ → Solubility ↑
B. KH ↑ → Solubility ↓
C. KH ↑ → Pressure ↓ necessarily
D. KH has no connection with solubility
Answer: B. KH ↑ → Solubility ↓
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