Multiply the volume in liters (4.00L) by the concentration of the solution in molar (0.250M) to calculate the number of moles of soluto that you need, then multiply the number of moles by the molar mass of sodium hydroxide (39.99 g/mol) to calculate the mass.
4.00L x 0.250 M x 39.99g / 1L = 39.99g
Basically you need one mol of NaOH (39.99g) dissolved in 4 liters of solution.
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.
Answer:
yeah the answer under the explanation
<em>Explanation:</em>
<em>The answer is (4) exothermic with ΔH = -1640 kJ. The 1640 kJ energy is at the right side of equation means that it releases energy. The enthalpy change means the energy of production minus the energy of reactants. If it is exothermic, the ΔH < 0.</em>
5.53*(6.023*10^23)= 33.30*10^27
Lemme look at the periodic table give me 1 minute
