4. To perform a certain activity assay it is necessary to have 0.25 mL of an enzyme at a concentration of 0.2 mgml¹ in the presence of 0.4 mM substrate and 200 mM NaCl in a suitable buffer. The stock solutions of enzyme, substrate and NaCl are 4 mgmL-¹, 40 mM and 1 M all in the same type of buffer. What volumes of the stock solutions and buffer are required for each assay?

Q7. Given the following Ka values for the weak acids and bases: CH;COOH/CH3CO0 HCO3/CO32- H2PO4 /HPO,2 Ка 1.8 х 105 Ka = 5.6 x 10:11 Ka = 6.2 x 108 Which of the pair(s) would be appropriate as a buffer at pH = 7.0? Explain your answer.

Please fill out the table and answer

The Mg2+ concentration in a saturated solution of magnesium hydroxide is measured and found to be 1.59 \times 10-4 M. Use this information to calculate a Ksp value for magnesium hydroxide.

Determine the solubility of aluminum hydroxide, Al(OH)3, in a buffer solution at a pH of 7.Ksp = 3.7E-15Include at least 3 significant figures in your answer.

Calculate the molar solubility of Ca(OH)2 in the presence of the dissolved CaCl2 Concentration of standardized HCl solution: 0.0646 M

What phenomenon is observed when the two solid starting materials are blended together? Why does this happen?

You made a pH 9.0 buffer solution at 25° C by mixing NaOH and histidine (HisH) to give a solution that is 0.200 M in total concentration of histidine. Deprotonation constants and enthalpies (heats) of deprotonation at 25°C Compound Deprotonation Histidine Water ▼ +H3NRH+COOH+H₂NRH COO + H+ +H3NRH+COOH3NRCOO¯ + H+ +H3NRCOO →H₂NRCOO + H H₂O-OH + H¹ Part O [Na] = Calculate the concentration of Na+ at 45 °C. Express your answer using two significant figures and include the appropriate units. Submit [H+] = 0 Ti μA Value Part N Request Answer μA Calculate the concentration of H+ at 45 °C. Express your answer using two significant figures and include the appropriate units. Value Submit Request Answer μA [OH-] = Value Submit Request Answer pK A, H° (kJ mol ¹) 1.80 6.04 9.33 14.00 Units 4 Units Calculate the concentration of OH at 45 °C. Express your answer using two significant figures and include the appropriate units. Units 29.9 46.6 55.82 ? ? ?

A student titrates a weak acid and draws the titration curve. Suppose s/he forgets to subtract off Vinitial from the volume data, causing the curve to be shifted to the right. (a) Will the calculated pKa be affected? Explain your answer. No X because the y-values are too high (b) Will the molar mass be affected? Explain your answer. No X because the x-values are too low

A student titrates a weak acid and draws the titration curve. Suppose s/he forgets to subtract off Vinitial from the volume data, causing the curve to be shifted to the right. (a) Will the calculated pKa be affected? Explain your answer. ---Select--- v| because the y-values are ---Select--- V (b) Will the molar mass be affected? Explain your answer. ---Select--- v because the x-values are ---Select---