5. As particle size of packing material in a column decreases for HPLC, the required solventpressure , the plate number , and the resolution?(A) increases; increases; decreases (B) decreases; increases; increases(C) increases; decreases; decreases (D) increases; increases; increases(E) decreases; decreases; decreases

7. A Na2CO3standard solution is prepared by transferring4.9634 grams of primary standard-grade sodium carbonate to a 500.0-mL volumetric flask, dissolving the sample in ~100 mLof distilled deionized water and diluted to the mark. A 50.00-mL aliquot is taken and titratedwith 85.30 mL of HCl solution. Calculate the concentration of the HCl solution. (Themolecular mass of Na2CO3 is 105.99 g/mol.)(A) 0.0549 M (B) 0.1098 M (C) 0.1598 M (D) 0.1997 M (E) 0.3196 M

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