Chemistry
Fill in the blanks:
(a) A reaction in which two or more substances combine to form a single substance is called a …………… reaction.
(b) A …………… is a substance which changes the rate of a chemical reaction without undergoing a chemical change itself.
(c) The formation of gas bubbles in a liquid during a reaction is called …………… .
(d) The reaction between an acid and a base is called …………… .
(e) Soluble bases are called …………… .
(f) The chemical change involving iron and hydrochloric acid illustrates a …………… reaction.
(g) In the type of reaction called …………… two compounds exchange their positive an negative radicals respectively.
(h) A catalyst either …………… or …………… the rate of a chemical change but itself remains …………… at the end of the reaction.
(i) The chemical reaction between hydrogen and chlorine is a …………… reaction.
(j) When a piece of copper is added to silver nitrate solution, it turns …………… in colour.
Related Questions
Assertion (A): When a copper coil is dipped in an aqueous solution of silver nitrate, the colour of the solution slowly changes from colourless to blue.
Reason (R): Silver metal is more reactive than copper.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): When energy is absorbed during a chemical reaction, it is said to be an exothermic reaction.
Reason (R): A rise in temperature takes place during an exothermic reaction.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Write true or false for the following and correct the false statements.
(a) When iron nails are put into a solution of copper sulphate, the solution becomes colourless after sometime.
(b) Burning of fuel in air produces a large amount of energy in the form of heat and light.
(c) Exchange of radicals takes place when calcium oxide reacts with water.
(d) A neutral oxide does not change the colour of an indicator.
(e) A white solid is produced when lead nitrate is heated.
Match the following :
Column A Column B (a) It changes the rate of a chemical reaction (i) Photosynthesis (b) Attractive force between the atoms to form molecules (ii) Amphoteric oxide (c) Oxides of non-metals (iii) Catalyst (d) Lead monoxide (iv) Chemical bond (e) Light energy (v) Acidic oxides