​Chemistry Topics

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A All Acid Bases And Indicators Acids Bases And Salts Air And Combustion Alkaline C Carbon And Its Compounds Chemical Families Chlorine And Its Compounds E Electric Current On Substance Electrochemistry I And Ii Energy Changes In Chemical And Physical Processes F Form 1 Level Form 2 Form 3 Form 4 G Gas Laws I Introduction To Chemistry K Kcse-1995 Kcse-1996 Kcse-1997 Kcse-1998 Kcse 1999 Kcse-2000 Kcse-2001 Kcse-2002 Kcse-2003 Kcse-2004 Kcse2005 Kcse-2005 Kcse-2006 Kcse2007 Kcse-2007 Kcse-2008 Kcse-2009 Kcse-2010 Kcse-2011 Kcse-2012 Kcse-2013 Kcse-2014 KCSE 2015 KCSE 2016 KCSE 2017 KCSE 2018 Kcse 2019 M Metals N Nitrogen And Its Compounds O Organic Chemistry I Organic Chemistry II P Paper 1 Paper 2 Periodictable Properties-and-trends-across-the-period R Radioactivity ​Reaction Rates And Reversible Reactions S Salts Simple Classification Of Substances Structure Of The Atom And The Periodic Table Structures And Bonding Sulphur And Its Compounds T The Mole W Water And Hydrogen

Use the information in the table above to answer the questions that follow

​a) i) Are the members in this group likely to be conductor or non – conductors? (1mk)

ii) Which element would have the lowest atomic number? Explain. (1mk)

​b) The grid below represents part of the periodic table. Study it and answer the questions that follow. (The letters are not the actual symbols of the elements)

b) The grid above represents part of the periodic table. Study it and answer the questions that follow. (The letters are not the actual symbols of the elements)

​i) Select the element in period three which has the shortest atomic radius. Give a reason for your answer. (2mks)

​ii) Using dots (•) and crosses (x) to represent outermost electrons, draw a diagram to show the bonding in the compound formed when chlorine reacts with element X (1mk)

½mk @ x 2 = 1mk Penalize fully if dots or crosses alone are used

​iii) When three liters of chlorine gas were completely reacted with element Y, 11.85g of the product were formed. Calculate the relative atomic mass of element Y. (3mks)

​(R.A.M of chlorine = 35.5, molar gas volume = 24 liters) 

Use the flow chart above to answer the questions that follow

​​a) Name the following;

​i) Gas L (1mk)

​ii) Gas H (1mk)

​iii) K (1mk)

​​b) Name the processes involved in the following steps

​i) Step I (1mk)

​ii) Step II (1mk)

​​iii) Step III (1mk)

​c) Draw the structure of compound E (1mk)

​d) Write a chemical equation for the complete combustion of substance F (1mk)

​e) Name the condition and reagents in step III 

​i) Condition (1mk)

​ii) Reagent (1mk)

​f) Calculate the mass of salt Q that would be formed by using 21.9kg of G when it reacts with excess sodium hydroxide (2mks)
(C = 120, H = 1.0, Na = 23.0, O = 16.0)

​g) i) Draw the structure of polymer D (1mk)

​ii) State one use of the above polymer (1mk)