Equilibrium is said to be attained in a reversible reaction when

• A) all the reactants have been used up
• B) all the products have been formed
• C) there is no further change in temperature
• D) the rate of forward and backward reactions are equal

Which of the following correctly explains entropy?

• A. the natural tendency for a system to achieve a greater disorder
• B. a balance of two driving forces between free energy and enthalpy changes
• C. the cause of spontaneity of a reaction
• D. a measure of the enthalpy of a reaction

The lanthanides and actinides are located in which block of the periodic table?

• A. P-block
• B. S-block
• C. F-block
• D. D-block

A gas sample with an initial volume of 3.25 dm³ is heated and allowed to expand to 9.75 dm³ at constant pressure. What is the ratio of the final absolute temperature to the initial absolute temperature?

• A. 3:1
• B. 5:2
• C. 5:4
• D. 8:3

Angiosperms and gymnosperms belong to the plants group known as

• A. schizophyta
• B. bryophyta
• C. pteridophyta
• D. spermatophyta

Which of the following compounds is a base?

• A. CO2
• B. CaO
• C. H3PO3
• D. CH3COOCH3

An example of an acid salt is

• A. CH₃COOONa
• B. Mg(OH)Cl
• C. NaHSO₄
• D. (NH₄)₂SO₄

When alkanols react with sodium, the ga evolved is

• A. hydrogen
• B. oxygen
• C. methane
• D. ethyne

The negatively charged particle in an atom is the

• A. Electron
• B. Neutron
• C. Positron
• D. Proton

What is eutrophication?

• A. The release of harmful chemicals into water bodies
• B. The excessive growth of algae due to nutrient enrichment
• C. The presence of heavy metals in water
• D. The formation of oil slicks on water surfaces