Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction?

• Endothermic and decreasing disorder

• Exothermic and increasing disorder

• Endothermic and increasing disorder

• Exothermic and decreasing disorder

Identify the correct statement for change of Gibbs energy for a system ($∆$G_system) at constant temperature and pressure

• If $∆$G_system = 0, the system has attained equilibrium

• If $∆$G_system = 0, the system is still moving in a particular direction

• If $∆$G_system = 0, the process is not spontaneous

• If $∆$G_system = 0, the process is spontaneous

The standard emf of a galvanic cell involving cell reaction with n = 2 is found to be 0.295 V at 25°C. The equilibrium constant of the reaction would be

• 2.0 × 10¹¹

• 4.0 × 10¹²

• 1.0 × 10²

• 1.0 × 10¹⁰

_nX^m emit one α and two β- particles. It is converted into

• _nX^{m - 4}

• _{n - 1}X^{m - 1}

• _nZ^{m - 4}

• None of these

18 carat gold contains

• 18% gold

• 24% gold

• 75% gold

• 60% gold

Which of the following metals will not form an amalgam?

• Gold

• Silver

• Zinc

• Iron

The element which liberates oxygen gas from water is

• P

• Na

• F

• I

Which is the weakest acid out out of HF, HCl, HBr and HI?

• HF

• HCl

• HBr

• HI

The strongest oxidising agent amongst F₂, Cl₂, Br₂ and I₂ is

• F₂

• I₂

• Cl₂

• Br₂

30.

A compound has the empirical formula CH₂O. Its vapour density is 30. Its molecular formula is

• C₂H₄O₂

• C₂H₆O

• C₂H₆O₂

• C₂H₄O