Chemistry Flashcards

Which of the following statements about SN1 reactions is correct?

Answer: They follow first-order kinetics

SN1 reactions follow first-order kinetics because the rate-determining step is the unimolecular ionization of the substrate to form a carbocation.

The molar conductivity of a weak electrolyte at infinite dilution can be determined using:

Answer: Kohlrausch's law

Kohlrausch's law states that molar conductivity at infinite dilution equals the sum of individual ionic conductances, applicable to weak electrolytes.

Which element shows the maximum tendency for catenation?

Answer: Carbon

Carbon shows maximum catenation due to its small size and strong C–C bond energy (~348 kJ/mol), forming stable long chains.

The reaction of glucose with acetic anhydride gives:

Answer: Glucose pentaacetate

Glucose has five –OH groups, so it reacts with acetic anhydride to form glucose pentaacetate.

Which of the following oxoacids of phosphorus is diprotic (dibasic)?

Answer: H₃PO₃

H₃PO₃ (phosphorous acid) is diprotic because one H is directly bonded to P (P–H bond), leaving only two ionizable –OH groups.

For the reaction N₂ + 3H₂ ⇌ 2NH₃, if pressure is increased at constant temperature, the equilibrium will:

Answer: Shift to the right

Increasing pressure shifts equilibrium to the side with fewer moles of gas; 4 moles → 2 moles, so equilibrium shifts right (toward NH₃).

The correct order of acidic strength among HF, HCl, HBr, HI is:

Answer: HI > HBr > HCl > HF

Acid strength increases down the group as bond dissociation enthalpy decreases; HI is the strongest acid and HF the weakest.