A buffersolution contains 0.1 mole of sodium acetate dissolved in 1000 cm³ of 0.1 M acetic acid. To the above buffersolution, 0.1 mole of sodium acetate is further added and dissolved. The pH of the resulting buffer is 

• pK_a

• pK_a + 2

• pK_a - log 

• pK_a + log 2

22.

H₂S is passed into one nm³ of a solution containing 0.1 mole of Zn²⁺ and 0.01 mole of Cu²⁺ till the sulphide ion concentration reaches to 8.1 × 10^-19 moles. Which one of the following statements is true?

[K_sp of ZnS and CuS are 3 × 10^-22 and 8 × 10^-36 respectively.]

• Only ZnS precipitates

• Both CuS and ZnS precipitate

• Only CuS precipitates

• No precipitation occurs

0.023 g of sodium metal is reacted with 100 cm³ of water. The pH of the resulting solution is

• 10

• 8

• 9

• 12

The empirical formula of a non-electrolyte is CH₂O. A solution containing 3 g of the compound exerts the same osmotic pressure as that of 0.05 M glucose solution. The
molecular formula of the compound is 

• CH₂O

• C₂H₄O₂

• C₄H₈O₄

• C₃H₆O₃

In an alkaline medium, glycine predominantly exists as/ in a/ an

• cation

• anion

• Zwitter ion

• covalent form

Which one of these is not true for benzene?

• It forms only one type of monosubstituted product

• There are three carbon-carbon single bonds and three carbon-carbon double bonds

• Heat of hydrogenation of benzene is less than its theoretical value

• The bond angle between carbon-carbon bonds is 120°

1.2 g of organic compound of Kjeldahlization liberates ammonia which consumes 30 cm³ of 1 N HCl. The percentage of nitrogen in the organic compound is

• 30

• 35

• 46.67

• 20.8

Carbon cannot reduce Fe₂O₃ to Fe at a temperature below 983 K because

• free energy change for the formation of CO is more negative than that of Fe₂O₃

• CO is thermodynamically more stable than Fe₂O₃

• carbon has higher affinity towards oxygen than iron

• iron has higher affinity towards oxygen than carbon

The yellow precipitate formed during the chromyl chloride test is chemically

• chromic acid

• lead chromate

• lead acetate

• sodium chromate

Which one of the following is true?

• NaOH is used in the concentration of bauxite ore

• NaOH is a primary standard in volumetric analysis

• Manganous hydroxide is soluble in excess of NaOH solution

• NaOH solution does not react with Cl