Question

please help biochem

Which range of pH is buffered by a oxalatic acid/sodium axalate buffer? 0 6.5-7.5 O 3-5 O 3.3-5.3 O 42-4.4 QUESTION 10 Which of the following would act as a buffer system? Select all that apply NH4 Cr CH3COOH and HC H3PO4 and NaH2PO4 CH3COOH and KCH3CO0 QUESTION 11 What ratio of 0.01M NaH2PO4 and 0.01 M NapHPO are needed to precare a buffer at ph of 7.0 1.3 NaH2PO4:10 NagHPO 075 NaH2PO 10 NazHPO 7.1 NaH2PO1.0 020 NaHPO 10 Naghpo tahall ah ou Gifoket Chck saend submit to snsd p QUESTION 3 molecule a molecule b HIC H,C HC molecule c molecule d Which of the following have non-polar properties? Select all that apply molecule a moleculeb molecule c molecule d molecule b molecule c molecule d QUESTION 4 molecule a molecule b H-C HC H.C molecule nolecule d Which of the following could be used to form blayers, Seiect alt that apply malecule molecuie b moecule c molecule d QUESTION 5 molecule d QUESTION 2 molecule a molecule b molecule d Which of the followng have polarproperties Select all that apply molecule a molecuie b molecule c molecule d QUESTION 3 ctck All eries molecule di QUESTION 5 Н,с- н,с- molecule a molecule c molecule b molecule d Which of the following can form hydrogen bonds? Select all that apply R Molecule a molecule b molecule c molecule d QUESTION 6 Absorption of drugs into the body is based on muitiple factorsincluding lohization state surface area of the momach and intestines and other physical propertes of the enue Anovel dut concains a carboolit acid functiona group with a pka value of 3.24 Based on jonzation states aone would you predict that it is becer absorbed le passes through a lpid membranel in.the stomach here the pH is about 2 orin the small intestines where the pH is about 8 in the stomach because the acid formis predom nant rerens in the stomach because the conugate pace is preao becaure the acid form isoredon n the smali intestines In the gmall intestines becaure the conjugate base s predominarcy prezent QUESTION 7 molecule a molecule b H-C H,C. A.c H,C H C molecule c molecule d Which of the following could be used to form bilayers. Select all that apply molecule a molecule b molecule c molecule d molecule c molecule d QUESTION 6 Absorption of drugs into the body is based on multiple factors including ionization state, surface area of the stomach and intestines, and other physical properties of the drug. A novel drug contains a carboxylic acid functional group with a pKa value of 3.24.. Based on ionization states alone, would you predict that it is better absorbed (ie passes through a lipid membrane) in the stomach where the pH is about 2, or in the small intestines where the pH is about 8? In the stomach, because the acid form is predominantly present. In the stomach because the conjugate base is predominantly present. In the small intestines, because the acid form is predominantly present In the small intestines, because the conjugate base is predominantly present 02 QUESTION 7 A dialysis bag contianing 2M glucose is placed in a 4.5M NaCI solution. In which direction does the water flow. There is no net flow of water QUESTION 9 Which range of pH is buffered by a oxalatic acid/sodium oxalate buffer? 6.5-7.5 3-5 3.3-5.3 4.2-4.4 QUESTION 10 Which of the following would act as a buffer system? Select all that apply NH4 C molecule a molecule b H,C S4 H,C. H,C HC H-C H C - molecule c molecule d Which of the following have non-polar properties? Select all that apply. molecule a molecule b molecule c molecule d 0.2 point molecule a molecule b H-C H.C H.C H,C H,C HC mo lecule c molecule d Which of the following have polar properties? Select all that apply. molecule a molecule b molecule c molecule d

Answer 1

1) The options for the first question are wrong.

the dissociation constant of oxalic acid, k_a is 6.0 x 10^-2. pK_a = -log k_a = -log ( 6.0 x 10^-2)= 1.22.

The range of pH buffered by oxalic acid and sodium oxalate is pH=pK_a $\pm$ 1 = 1.22 $\pm$ 1.

so, the range would be 0.22 to 2.22.

11) the correct option is the second one. 0.75 NaH₂PO₄ and 1.0 Na₂HPO₄