Chemistry Mcqs Set 56

Chemistry Mcqs Set 56

1. 100 ml of oxygen gas and 100 ml of nitrogen gas at normal temperature and pressure contain ................
(i) equal number of atoms                        
(ii) equal number of molecules
(iii) oxygen gas has more number of atoms than nitrogen gas
(iv) nitrogen gas has more number of atoms than oxygen gas
 
2. Identify the monatomic and diatomic species from the following pairs .............
(i) helium and neon                  
(ii) hydrogen and chlorine
(iii) chlorine and ozone             
(iv) helium and oxygen
 
3. The atomic mass of ozone is 16 and its molecular mass is 48. It atomicity is ............
(i)16/48                
(ii) 48/16                     
(iii) 48 x 16               
(iv) 48+16
 
4. The molecular mass of chlorine is 71 and its atomic mass is 35.5. The atomicity of chlorine is ........................
(i) 1                    
(ii) 2                   
(iii) 3                 
(iv) cannot be predicted
 
5. the atomic mass of sulphur is 32. It has atomicity 8. The molecular mass of sulphur is .............
(i) 32         
(ii) 256                      
(iii) 4                     
(iv) 42
 
6. The atomic and mass numbers of certain elements are given as:
1. 35Cl17 ; 40Ar18               
2. 35Cl17 ; 35Cl17                    
3. 8O17 ; 8O17                         
4. 40Ar18 ; 40Ca20
these pairs , the pair which is known as isotopes are .....................
(i)1 and 2                     
(ii) 2                      
(iii) 2 and 4                      
(iv) 3 and 4
 
7. Isobars are ..................
(i) atoms of the same element with same atomic number but different mass number
(ii) atoms of different elements having the same mass number but different atomic number
(iii) atoms of different elements with the same number of neutrons
(iv) atoms of different elements having the same atomic number and different mass number
 
8. 6C14 and 7N14 are examples of ........................
(i) isotopes                
(ii) isobars                  
(iii) isotones                 
(iv) isosters
 
9. Which of the following statement truly reflect the definition of atom and molecule?
(i) atoms are unstable and do not exist free whereas molecules exist free
(ii) atoms of polyatomic molecules do not exist free whereas molecules exist free
(iii) atoms of all types of molecules and molecules exist free
(iv) monoatomic elementary molecule and molecules do not exist free
 
10. Which of the following have independent existence?
(i) an atom of nitrogen                          
(ii) an atom of helium
(iii) a molecule of chloride                     
(iv) both (ii) and (iii)