(a) On heating, magnesium ribbon burns in air with the formation of a white powder called .................

(b) The substances which undergo chemical change are called ................

(c) AgNO_³ + NaCl AgCl + ............... .

(d) Decomposition of potassium chlorate on heating in the presence of manganese dioxide gives ............... .

(e) Unbalanced reaction is also known as ............ .

(f) Reaction in which energy is absorbed is known as ............... reaction.

(a) The number of atoms of each element is conserved in any chemical reaction.

(b) Hydrogen sulphide has a smell that of a rotten egg

(c) The reaction between hydrogen and chlorine is an example of combination reaction

(d) The reaction between hydrogen and chlorine is an example of combination reaction.

(e) A black residue is formed when sugar is heated.

(f) Action of heat on ferrous sulphate is an example of decomposition reaction.

(2) What is a chemical equation?

(5) What is Law of Conservation of Mass?

(4) What is rust?

(1) What is a chemical reaction ?

(3) Give an example of exothermic reaction

(1) Write the characteristics of a chemical equation.

(2) Balance the following chemical equation: (i) H₂ + N₂ NH₃ (ii) MnO₂ + HCl MnCl₂ + Cl₂ + H₂ O

(3) List some characterstics of chemical changes

(4) What happen when an iron nail is dipped into the copper sulphate solution?

(2) Write the word equations for the following skeletal equations. (i) Zn + HCl ZnCl2 + H2 (ii) CO + O2 CO2 (iii) AgBr Ag + Br

(1) Explain the following with examples: (i) Combination reaction (ii) Decomposition reaction (iii) Simple displacement reaction

(3) Write your observation for the following chemical reactions and name the products obtained: (i) Dilute acetic acid is poured on baking soda (ii) Sodium carbonate reacts with hydrochloric acid (iii) Calcium carbonate is heated.

MgO

law of conservation of mass

all of the above

black

Yellow ppt of lead iodide formed