(1) The weak monoprotic acid HA is 2.5% dissociated in 0.10 mol·L-1solution. What is the acidity constant, Ka, of HA?(2)A certain solution of HA has a pH=2.51. What is the concentration of the solution?

A 1 M solution of glucose contains _____ g/L of glucose. A: 18 B: 128 C: 168 D: 180

In c (H2C2O4) = 1.0 mol/L H2C2O4 solution, the hydrogen ion concentration is 2.0 mol / L.

Of the following buffer solutions, the one with the strongest buffer is A: 0.1mol·L-1NH3·H2O solution and 0.1mol·L-1NH4Cl solution are mixed in equal volumes B: 0.2mol·L-1NH3·H2O solution and0.2mol·L-1NH4Cl solutionare mixed in equal volumes C: 0.2mol·L-1NH3·H2O solution and0.2mol·L-1NH4Cl solutionare mixedat a volume ratio of 2:1 D: 0.1mol·L-1NH3·H2O solution and0.2mol·L-1NH4Cl solutionare mixedat a volume ratio of 2:1

What is the volume ratio of HCl solutionto NH3·H2O (pKb=4.75)solution when abuffer solution atpH9.25 is prepared with the same concentration of HCl solutionand NH3·H2Osolutions A: 1:1 B: 1:2 C: 2:1 D: 3:1

Fehling's solution consists solution of A and B, a solution of ____, and a solution of potassium sodium copper tartrate.

The sequence of reagents used in Gram staining is () A: Safranin solution → iodine solution → alcohol →<br/>crystal violet B: crystal violet → alcohol → iodine solution → Safranin<br/>solution C: Crystal violet → iodine solution → alcohol → Safranin<br/>solution D: Safranin solution → alcohol → crystal violet → iodine<br/>solution E: Safranin solution → crystal violet → iodine solution →<br/>alcohol

Transporting the trash to the rural areas is considered as______. A: an effective solution B: a costly solution C: a dangerous solution D: a feasible solution

Compared with plasma, which solution belongs to isotonic solution? ( ) A: 9 g•L-1 NaCl solution B: 90 g•L-1 NaCl solution C: 10 g•L-1 glucose solution D: 6.25 g•L-1 NaHCO3 solution

What is the pH value of 0.1 mol/L HA solution? pKa (HA) = 5.0 ( ) A: 6.0 B: 8.0 C: 7.0 D: 9.0