csir net life science question paper solved part b

Tris hydroxyethyl aminoethane (THAE) has a pk, of 8.4. The buffering capacity of a buffer made with this compound will be greatest at which pH?

by

Tris hydroxyethyl aminoethane (THAE) has a pk, of 8.4. The buffering capacity of a buffer made with this compound will be greatest at which pH? (1) pH 9.4 ffer (2) pH 7.4 (3) pH 8.4 (4) Both at pH 7.4 and 9.4 Concept: Buffering Capacity and pKa The buffering capacity of a buffer is highest … Read more

What is the concentration of OH in a solution with a H’ concentration of 1.3 * 10 ^ – 4 M?

by

What is the concentration of OH in a solution with a H’ concentration of 1.3 * 10 ^ – 4 M? (1) 7.7 * 10 ^ – 10 * M (2) 7.7 * 10 ^ – 9 * M (3) 7.7 * 10 ^ – 11 * M (4) 7.7 * 10 ^ – 12 … Read more

If pH of solution of NaOH is 12.0 the pH of H2 SO4 solution of same molarity will be

by

If pH of solution of NaOH is 12.0 the pH of H2 SO4 solution of same molarity will be (1) 2.0 (3) 1.7 (2) 12.0 (4) 10.0387

A 10 N HCI solution was diluted 10-fold with water and the pH of the diluted solution was measured with a pH meter after calibration using standard solutions. Given that the activity coefficient for diluted HCI was 0.01, the pH of the solution would be

by

A 10 N HCI solution was diluted 10-fold with water and the pH of the diluted solution was measured with a pH meter after calibration using standard solutions. Given that the activity coefficient for diluted HCI was 0.01, the pH of the solution would be (1) 0 (3) 2 (2) 1 (4) 2.5

The pka of acetic acid is 4.76. At what pH would the concentration of acetic acid and acetate ion be the same?

by

The pka of acetic acid is 4.76. At what pH would the concentration of acetic acid and acetate ion be the same? (1) pH = 7 (3) pH = 9.8 (2) pH = 6.7 (4) pH = 4.76

Which one of the following amino-containing buffering molecules will be the most able to resist change in pH when in a pH 7.0 solution at a total (ionized and non-ionic) concentration of 100mM?

by

Which one of the following amino-containing buffering molecules will be the most able to resist change in pH when in a pH 7.0 solution at a total (ionized and non-ionic) concentration of 100mM? (1) Tris (pKa = 8.1) (3) MOPS {pKa = 7.3} (2) HEPES (pKa = 7.7) (4) PIPES (pKa = 7.1) Concept: Best … Read more

While making 100 ml of 2M NaCl solution, a student left the solution on a heating platform reducing the volume by 50 ml. This solution was diluted 1:100 for use. What is the final concentration of NaCl in this solution?

by

While making 100 ml of 2M NaCl solution, a student left the solution on a heating platform reducing the volume by 50 ml. This solution was diluted 1:100 for use. What is the final concentration of NaCl in this solution? (1) 20 mM (3) 40 mM (2) 80 mM (4) 400 mM

A TE buffer contains 200 mM Tris and 50 mM EDTA. Given the stock solutions-0.5 M Tris and 0.5 M EDTA, volumes of stock solutions required to make 1 liter of buffer solution are respectively.

by

A TE buffer contains 200 mM Tris and 50 mM EDTA. Given the stock solutions-0.5 M Tris and 0.5 M EDTA, volumes of stock solutions required to make 1 liter of buffer solution are respectively. (1) 400 ml, 100 ml (3) 500 ml, 125 ml (2) 200 ml, 50 ml (4) 100 ml, 25 ml

Two solutions of a substance (non-electrolyte) are mixed in the following manner: 480 ml of 1.5 M first solution+ 520 ml of 1.2 M second solution. What is the molarity (M) of the final mixture?

by

Two solutions of a substance (non-electrolyte) are mixed in the following manner: 480 ml of 1.5 M first solution+ 520 ml of 1.2 M second solution. What is the molarity (M) of the final mixture? (1) 1.250 (3) 1.433 (2) 1.344 (4) 1.479