Important Question of Chemistry 11 Ch 1

Table of Contents

 One Mark questions with answers 

1. What is the significant figures in 1.050 x 10⁴? 

Ans. Four 

2. What is the S.I. unit of Density? 

Ans. Kg m^-3 

3. What do mean by Mole fraction? 

Ans. Mole Fraction is the ratio of number of moles of one component to the total  number of moles (solute and solvents) present in the solution. It is  expressed as 'x'. 

4. Round off up to 3 significant figure (a) 1.235 (b) 1.225 Ans. (a) 1.24 (b) 1.22 

5. What is AZT? 

Ans. Azidothymidine. 

6. What is limiting reagent? 

Ans.The reactant which gets consumed first or limits the amount of product  formed is known as limiting reagent 

7. Define one mole? 

Ans. One mole is the amount of a substance that contains as many particles as  there are atoms in exactly 12 g of the carbon-12. 

8. Calculate the formula mass calcium chloride. 

Ans. Formula mass of CaCl₂= 40+2 x35.5=40+71 =

u 

9.What is the law called which deals with the ratios of the volumes of the  gaseous reactants and products? 

Ans. Gay Lussac’s law of gaseous volumes. 

Two Marks questions with answers 

1. Give the two points of differences between homogeneous and heterogeneous  mixtures. 

Ans.

Homogeneous mixture	Heterogeneous mixture
1. Homogeneous mixtures  have the same composition  throughout the sample.   2. The components of such  mixtures cannot be seen  under a powerful  microscope.	1. Heterogeneous mixtures consist of  two or more parts (phases), which  have different compositions.   2. These mixtures have visible  boundaries of separation between the  different constituents and can be seen  with the naked eye

2. What is the difference between 160 cm and 160.0 cm 

Ans. 160 has three significant figures while 160.0 has four significant figures.  Hence, 160.0 represents greater accuracy