Physical And Ch...

An example of a chemical change is:

Study the Venn diagram given below and the table that follows.

Analyse the two statements given below and select the correct option.

Statement I: Both physical and chemical changes may be accompanied by a change in state.
Statement II: Boiling of water is a chemical change because a gaseous product is formed.

While balancing an equation, which of the following is changed?

Analyse the given statements and choose the correct option:

A. Formation of a precipitate on mixing two solutions is a sure indication of a chemical change.
B. Both physical and chemical changes are associated with energy exchanges.
C. Occurrence of effervescence during a reaction indicates that the reaction mixture is boiling.
D. A colour change indicates that the reaction cannot be reversed by any physical or chemical means.

Identify the type of the given reaction:

2H₂O 2H₂ + O₂

Identify the type of the given reaction:

C₂H₆ + 5O₂ 3H₂O + 2CO₂

What will be the respective coefficients in the given chemical equation?

?Mg + ?HCl 1MgCl₂ + ?H₂

Refer to the flow chart given below and identify the incorrect statements regarding W, X, Y and Z.



I. W is a combination reaction.
II. W is always an endothermic process.
III. X could be a neutralisation reaction.
IV. Y could be the reaction of an acid with some metal bicarbonate.
V. Y could be a displacement reaction.

Which of the following reactions is a double displacement reaction?

A man painted his main gate that was made of iron. This is done in order to

(i) prevent it from rusting
(ii) protect it from the sunlight
(iii) make it look beautiful
(iv) make it dust free

Which of the above reasons is/are correct?

Corrosion is a chemical reaction that involves

During an activity, following three test tubes are set up:

Test tube 1: A shiny iron nail is placed in a test tube along with anhydrous calcium chloride. Mouth of the test tube is covered with cotton wool.
Test tube 2: A test tube is filled with boiled water and a shiny nail is dropped in it. A layer of oil is placed on the surface of water.
Test Tube 3: A test tube is filled with tap water and a shiny iron nail is dropped in it. The test tube is left open.

In which of the test tubes will rusting not take place when observed after a week?

Identify the incorrect statement(s).

Statement I: All physical changes are spontaneous, but chemical changes have to be induced.
Statement II: All changes, physical as well as chemical, involve energy exchanges.

Match the following:

A. BaCl2 + Na2SO4 BaSO4 + 2NaCl	(i) Combination reaction
B. Mg + H2O MgO + H2	(ii) Double displacement reaction
C. 2KClO3 2KCl + 3O2	(iii) Decomposition reaction
D. C + O2 CO2	(iv) Displacement reaction

Zinc oxide (ZnO) reacts with carbon (C) to produce zinc (Zn) and carbon monoxide (CO). The balanced chemical equation for the given reaction is ZnO (s) + C (s) Zn (s) + CO (g). Which of the following substances is reduced in the given reaction?

Which of the following statements is true about the reaction of copper turnings with the silver nitrate solution?

Which of the following statements is not true about a substance that goes rancid?

Which of the following phenomena is not an indication of a chemical change?

The substances which prevent oxidation of food are called