Question

1. 1x10^-9 moles of strong acid HCl are added to of water (total volume is 1L). the pH of the resulting solution is...

a)9

b)8

c)7

d)5

e)2

I got 9 but got the answer incorrect, so i would like to know how to solve this properly and what is the final answer.

2. the pKa of acetic acid is 4.76. if the pH=4.76 and the concentration of sodium acetate is 0.1M, what is the concentration of acetic acid?

a)0.05 M

b)0.10M

c)0.20M

d)4.76M

3. the pH of a sample of blood is 7.4. the pH of a sample of gastric juice is 1.4. the blood sample has...

a) 5.29 times lower [H3O+] than gastric juice

b) 6 times lower [H3O+] than gastric juice

c) 6000 times lower [H3O+] than gastric juice

d) 1,000,000 times lower [H3O+] than gastric juice

e) none of the above is correct

4. the approximate molecular weight of alanine is 89.1g/mol at pH=7. what is the approximate molecular weight of alanine-alanine dipeptide (Ala)2 at pH=7?

5. for amino acids with R groups that DO NOT TITRATE, the net charge on the amino acid when the pH <pI is:

a)neutral

b)negative

c)positive

d)equally positive and negative

e) not enough information

6. calculate the pH of a mixture of 100mL 1M acetic acid, 100mL of 1M sodium acetate, and 27mL of 1M HCl in final volume of 1L with distilled water. the pKa of acetic acid is 4.76. show all work please.

Answer 1

oncenhahon mole mole volume cententothon L. eluso cate-tompleteltーtn.ay Hi BH: Hence t ohtun d c) e. 그 s correct Since hle are enhtled h anuuet only fist 一guichon : There fort, Tarn-anueting-tin kindly host diffcunt qucthions scharaicly leue Rate Thank Yos -quieten y o nl ate tatill be hathy to hel? you O U