I. A bottle contains an aqueous solution of pH 45. The hydro (c) 522x10 M 4.22x1
ID: 524328 • Letter: I
Question
I. A bottle contains an aqueous solution of pH 45. The hydro (c) 522x10 M 4.22x10 of (OH) concentration such a solution is (a) 3.22x10 (d) 6.22x10 (e) None of the above 2. The H ion concentration, pl, oH ion concentration and poll of a 0.001 M solution a) 2, 10 M and of Ca(OEph are (a) 2.5, 10 M and respectively M. 2.3. 10 M and 14 (c) 0.003M, 2.2, 10'' M and 8 respectively (d)0.000s respectively (e) None of the above. 3. A segment of a DNA chain with the base sequence TCAGAT would be transcribed by RNA pol to an RNA chain with which of the following base sequences? (a) CUAAGU AGUCUA (c) AG TCTA, (d) AUCUGA (e) ATCTGA 4. Which of the following ionic species of glutamic acid would be most prevalent at pH 7? (a) HOOC-CN Ha-H-( H (b) TOOC-CN H H-(CHz)rCOOH (c) OOC- biological membranes, proteins and lipids interact mainly by (a) Hydrophobic interactions (b) Hydrogen bonding (c) Hydrophilic interactions (d) lonic bonds. 6. Sucrose is a which is made up of (a) glucose and sucrose (b) glucose and fructose (c) glucose and glucose (d) fructose and fructose (e) glucose and galactose. 7. Peptide bond synthesis requires an input of energy during (a) Amino acid activation (b) The binding of the aminoacyl-tRNA to the A site on the ribosome (c)The movement of the peptide-tRNA to the P site and the associated movement of the mRNA (d) All of the above. 8. At pH 7.0, the net charge on the peptide -Ala-Gly-Glu-Pro- would be (a) -2 (b) -1 (c 0 (d) +1 (e) +2. 9. Name all the amino acids with basic side chains:Explanation / Answer
Question 1.
H2SO4, sufuric acid
pH = 4.5
given pH, find [OH-] = ?
from pH, get pOH
pOH = 14-pH = 14-4.5 = 9.5
get OH- from pOH
[OH-] = 10^-pOH = 10^-4.5 = 0.00003162277 M
Question 2.
For
[H+] given Ca(OH)2 --> 0.001 M
calculate first OH- ions
[OH-] = 2*[Ca(OH)2] = 2*0.001 = 0.002 M
then
pOH = -log(OH) = -log(0.002) = 2.6989
pH = 14-2.6989
pH = 11.3011
[H+] = 10^-pH = 10^-11.3011 = 4.9991*10^-12