---

Which of the following statements are true for pure substances?
(i) Pure substances contain only one kind of particles
(ii) Pure substances may be compounds or mixtures
(iii) Pure substances have the same composition throughout
(iv) Pure substances can be exemplified by all elements other than nickel

(ii) and (iii)(iii) and (iv)(i) and (iii)(i) and (ii)

---

Rusting of an article made up of iron is called

dissolution and it is a chemical changecorrosion and it is a chemical changedissolution and it is a physical changecorrosion and it is a physical as well as chemical change

---

A mixture of sulphur and carbon disulphide is

homogeneous and does not show Tyndall effectheterogeneous and does not show Tyndall effecthomogeneous and shows Tyndall effectheterogeneous and shows Tyndall effect

---

Tincture of iodine has antiseptic properties. This solution is made by dissolving

iodine in alcoholiodine in wateriodine in vaselineiodine in potassium iodide

---

Which of the following are homogeneous in nature?
(i) ice (ii) wood (iii) soil (iv) air

(iii) and (iv)(i) and (iv)(ii) and (iv)(i) and (iii)

---

Which of the following are physical changes?
(i) Melting of iron metal
(ii) Rusting of iron
(iii) Bending of an iron rod
(iv) Drawing a wire of iron metal

(ii), (iii) and (iv)(i), (iii) and (iv)(i), (ii) and (iv)(i), (ii) and (iii)

---

Which of the following are chemical changes?
(i) Decaying of wood
(ii) Burning of wood
(iii) Sawing of wood
(iv) Hammering of a nail into a piece of wood

(i) and (iv)(iii) and (iv)(ii) and (iii)(i) and (ii)

---

Two substances, A and B were made to react to form a third substance A₂B, according to the following reaction.
2A + B → A₂B
Which of the following statements concerning this reaction are incorrect?
(i) The product A₂B shows the properties of substances A and B
(ii) The product will always have a fixed composition
(iii) The product so formed cannot be classified as a compound
(iv) The product so formed is an element

(ii), (iii) and (iv)(i), (iii) and (iv)(ii), (iii) and (iv)(i), (ii) and (iii)

---

Two chemical species X and Y combine together to form a product P which contains both X and Y
X + Y → P
X and Y cannot be broken down into simpler substances by simple chemical
reactions. Which of the following concerning the species X, Y and P are correct?
(i) P is a compound
(ii) X and Y are compounds
(iii) X and Y are elements
(iv) P has a fixed composition

(i), (iii) and (iv)(ii), (iii) and (iv)(i), (ii) and (iv)(i), (ii) and (iii)