Chemistry Questions and Answers - Form 1 Mid Term 2 Exams 2021

CHEMISTRY
FORM 1
MID TERM 2

INSTRUCTIONS:

• Answer all the questions

1.      
   1. What is Chemistry? {1mk}
   2. Define the following terms as used in chemistry;
      1. Matters {1mk}
      2. Mixture {1mk}
2. Explain how you would distinguish a solid from a liquid {2mks}
3.              
   1. what is a drug {1mk}
   2. State two long term effects of drug abuse to the user {2mks}
   3. A form one student went to the school clinic and was prescribed malarial drugs to take 2 x3
      1.  Explain how the student was supposed to take the drugs {2mks}
      2. Supposing the student took the drugs at 7.00a.m in the morning. Calculate the other hours of the day when he is expected to take the other drugs {2mks}
4. State three ways in which chemistry has helped improve living standards in the society {3mks}
5.            
   1. State any four difference between luminous and non-luminous flame {4mks}
6.         
   1. Other than Bunsen burner name two other apparatus that are used in heating substances in the laboratory {2mks]
   2. Most of the laboratory apparatus are made of glass. Give three reasons {3mks}
   3. Name the apparatus used to measure the following;
      1. Accurate volume of liquids {three apparatus } {3mks}
      2. Amount of solid [one] apparatus {1mk}
      3. Temperature of boiling water [one]apparatus {1mk}
7. Putting off flames not in use is one of the safety rules of laboratory to avoid injuries. List four other safety rules applied {4mks
8. Draw and label a non-luminous flame {4mks}
9.          
   1. Name three major parts of bursen burner {3mks}
   2. State the functions of each of the part named in {a} above {3mks}
10. The diagrams below are some common laboratory apparatus. Name each apparatus and state its use{8mks}
    

    	Apparatus	Name	Use
    i
    ii
    iii
    iv

11.          
    1. What is a flame {1mk}
    2. Wooden splint W and Y were placed in different zones of a bursen burner flame. The diagram below shows the observations that were made
       
       
       1. State the zone of the flame that made
          1. the observation for W {2mks}
          2.  the observation for Y
       2. Explain the difference between W and Y {2mks}
       3. Identify the most ideal flame used in the experiment above {1mk}
12. Study the set-up shown below and answer the questions that follow;
    
    
    1. Name:
       1. Apparatus A {3mks}
       2. Apparatus C
       3. Apparatus D
    2. Name the method of separation shown above {1mk}
    3.          
       1. Distinguish between a filtrate and residue {2mks}
       2. Identify them from the set-up above {2mks}
       3. Why is it possible to separate the mixture above using the method named in {b} above{1mk}
13. The set-up below was used to separate a mixture of liquid M and N with boiling points of 680C and 780 respectively by the use of method K
    
    1. Name the method K {1mk}
    2. Name the apparatus {5mks}
       1. A
       2. B
       3. C
       4. D
       5. F
    3. State two properties of liquid M and N that makes them possible to separate by method K shown above {2mks}
    4. State one function of glass beads {1mk}
    5. Which letter represent;
       1. Water outlet in apparatus C {1mk}
       2. Water inlet in apparatus C {1mk}
    6. What is the effect of interchanging the water inlet and water outlet in apparatus C {1mk}
    7. What general name is given to the liquid collected in apparatus p {1mk}
    8. Give an example of two liquids that can be separated by method K {1mk}

MARKING SCHEME

1.    
   1. chemistry is the study of the structure, properties and composition of matter and the changes that matter undergoes. √1
   2.    
      1. Matter is anything that has mass and occupies space. √1
      2. Mixture consists of two or more substances mixed together with the individual components forming the mixture retaining their physical and chemical properties. √1
2.         
   1. A solid has definite shape that is not easily changed while a liquid take the shape of the container. √1
   2. Solids have no ability to flow while liquids are able to flow. √1
3.          
   1. A drug is any substance natural or manufactured which when used alters the way the body functions. √1
   2.       
      1. Addiction √1
      2. Dependency √1
      3. mental disorder
         Any two correct
   3.         
      1. 243 =8hrs√1
         The student is to take 2tablets after every 8hrs. √1
      2. 7:00hrs
         8:00
         15:00hrs √1
         8:00
         23:00hrs √1
4.            
   • manufacture of drugs to fight diseases. √1
   • Food production to fight hunger. √1
   • Manufacture of detergents. √1\
5.     
   

   Luminous	Non- Luminous
   Flame is not noisy	Flame is noisy √1
   Yellow flame	Blue flame √1
   Produces soot	Does not produce soot √1
   Large and wavy	Small and steady √1

   
   Any 4 correct
6.          
   1.         
      1. portable burner √1
      2. gas stove √1
      3. candle
         Any 2 correct
   2.             
      • Easy to clean √1
      • for easy making of observation since the apparatus are transparent √1
      • do not react with most reagents used in the laboratory √
   3.         
      1. Burette √1
         Syringe √1
         Pippete √1
         Volumetric flask √1
      2. Weighing balance/ electrical balance √1
      3. Thermometer √1
7.          
   1. Never smell gases directly instead waft the gas towards the nose with your hand.
   2. Incase of accident such as fire calmly walk out
   3. Label all the chemicals you are using to avoid confussion
   4. Always consult your teacher before trying any experiment to avoid accidents.
      Any 4 correct
8.       
   
9.       
   1.        
      1. Base √1
      2. Chimney √1
      3. Collar √1
   2.     
      1. Base – provides support √1
      2. Chimney- ensures that gas and air mix before they start burning at the upper end of the chimney. √1
      3. Collar- helps to regulate the amount of air entering the chimney. √1
      4. a flame is a mass of burning gases √1
10.    
    

    	Apparatus	Name	Use
    i		Round bottomed flask	Used when heating liquid substances because heat is supplied uniformly so that the flask does not crack as it expands. √1
    ii		Thistle funnel	Used for delivering liquid substances
    iii		Pippete	Used to measure accurate volume
    iv		Deflagrating Spoon	Used for holding substances being burned

        
    
    
11.         
    1.        
       1.    
          • almost colorless √1
          • pale blue zone √1
       2. W is partly burnt because the wooden splint was placed on the cooler regions of e flame √1 while Y was burnt uniformly because the flame at that region is hotter. √1
       3. Non- Luminous flame √1
12.          
    1.           
       1. A- conical flask √1
       2. C- filter paper √1
       3. D- Beaker √1
    2. Filtration √1
    3.     
       1. Filtrate is the liquid that passes through the filter paper √1 while residue is the solid that remains on the filter paper when filtering. √1
       2. Filtrate- Liquid P √1
       3. Residue- solid K √1
       4. They are immiscible substances √1
13.          
    1. Fractional Distillation √1
    2.         
       1. Thermometer √1
       2. Fractionating Column √1
       3. Lie- big condenser √1
       4. Clamp and stand √1
       5. Tripod stand √1
    3.     
       1. Are miscible liquids √1
       2. Different but close boiling points √1
    4. To increase the surface area for the condensation of vapour coming from the distillation flask. √1
    5.         
       1. K √1
       2. L √1
    6. If the water inlet and outlet are interchanged condensation would not occur efficiently or effectively. √1
    7. Distillate √1
    8. Ethanol and water, propanone and ethanol, propanol and water. √1
       Any 2 correct