In which of the following chemical equations, the abbreviations represent the correct states of the reactants and products involved at reaction temperature?

Which of the following is(are) an endothermic process(es)?

(i) Dilution of sulphuric acid

(ii) Sublimation of dry ice

(iii) Condensation of water vapours

(iv) Evaporation of water

In the double displacement reaction between aqueous potassium iodide and aqueous lead nitrate, a yellow precipitate of lead iodide is formed. While performing the activity if lead nitrate is not available, which of the following can be used in place of lead nitrate?

Which of the following are combination reactions?

(i) 2KClO₃ 2KCl + 3O₂

(ii) MgO + H₂O → Mg(OH)₂

(iii) 4Al + 3O₂→ 2Al₂O₃

(iv) Zn + FeSO₄→ ZnSO₄ + Fe

Write true or false for the following statements:

On heating the crystals of ferrous sulphate, the colour changes from green to grey.