If the conjugate base of a molecule has a pKb of 1.4, the molecule should be a Weak Acid.
Notice this question gives us the pKb of the molecule, not the pKa. Because of this, the pH scale basically gets reversed, so lower numbers in pKb correlate with stronger bases, and higher numbers in pKb correlate with stronger acids - the exact opposite of the pH scale.
It's important to make sure you completely understand the terms of conjugate base, conjugate acid, pKb, pKa, and how they all relate. It's easy to mix up the meanings of these definitions.
Here are the two other pieces of information you need to know to correctly answer this question:
- Strong acids have a weak conjugate base.
- Strong bases have a weak conjugate acid.
So if the problem says you have a strong conjugate base, then the molecule must be a weak acid. To illustrate this, think of ammonium, NH4+. Ammonium is a weak acid, but the conjugate base of ammonium is ammonia, NH3, which is a reasonably good base.
Learn more about conjugate base here : brainly.com/question/22514615
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Protium - the most common isotope of hydrogen - has no neutrons in its nucleus.
Its condensation
the vapour has a lot of kinetic energy but if it cools down it loses that energy and condenses into a liquid
hope that helps
Answer:
a) No. of moles of hydrogen needed = 5.4 mol
b) Grams of ammonia produced = 27.2 g
Explanation:
a)
No. of moles of nitrogen = 1.80 mol
1 mole of nitrogen reacts with 3 moles of hydrogen
1.80 moles of nitrogen will react with
= 1.80 × 3 = 5.4 moles of hydrogen
b)
No. of moles of hydrogen = 2.4 mol
It is given that nitrogen is present in sufficient amount.
3 moles of hydrogen produce 2 moles of 
2.4 moles of hydrogen will produce
= 
Molar mass of ammonia = 17 g/mol
Mass in gram = No. of moles × Molar mass
Mass of ammonia in g = 1.6 × 17
= 27.2 g
Answer:
Explanation:
As the pH drops, the NH2groups on the lysine side chains become charged and helices can no longer form because of charge repulsion between these groups. This might occur below the pKa of lysine if more than 50% of the lysine residues is to be charged in order to ‘break’ the helix. Another possibility is that the pKa of lysine residues might be different when in polylysine as compared with the monomer (free amino acid) in solution.
One will expect other residues that are positively charged at neutral pH to have a similar profile; namely, arginine and possibly histidine. Both arginine and histidine are bulkier than lysine. Even if there were some rotation of their side chains, steric interference would probably be so severe as to prohibit the formation of an -helix. The transition is inverted because at a low pH glutamate will be neutral whereas at a high pH it will assume a net negative charge (through dissociation of the carboxyl groups on its side chains). One will easily speculate that a polypeptide chain containing both glutamate and lysine residues will be able to form an helix at relatively neutral pHs. Under these conditions, lysines will be mostly positively charged and glutamates will be mostly negatively charged. This will allow these residues to make ionic bonds and salt bridges to stabilize the helix. At very low pH, however, lysine will be mostly positively charged, but it will be near to neutral glutamate residues. At very high pH, the Glu will be negatively charged, but it will be near neutral.
