Exam (elaborations)
Test (elaborations) All
- Course
- Institution
My documents is not fake but is uch hard but is help ful to high score
[Show more]
Seller
Follow
jitenderkumarjitender
Content preview
Intext Exercise 1Question 1:
Why should a magnesium ribbon be cleaned before burning in air?
Solution 1:
Magnesium is very reactive metal. When stored it reacts with oxygen to form a layer
magnesium oxide on its surface. This layer of magnesium oxide is quite stable and prevents
further reaction of magnesium with oxygen. The magnesium ribbon is cleaned by sand paper
to remove this layer so that the underlying metal can be exposed into air.
Question 2:
Write the balanced equation for the following chemical reactions.
(i) Hydrogen + Chlorine Hydrogen chloride
(ii) Barium chloride + Aluminium sulphate Barium sulphate +Aluminium chloride
(iii) Sodium + Water Sodium hydroxide + Hydrogen
Solution 2:
i H2( g ) Cl2( g ) 2HCl( g )
ii 3BaCl2( s) Al2 SO4 3( s) 3BaSO4( s) 2 AlCl3( s)
iii 2Na( s) 2H2O(l ) 2NaOH(aq) H2( g )
Question 3:
Write a balanced chemical equation with state symbols for the following reactions.
(i) Solutions of barium chloride and sodium sulphate in water react to give insoluble barium
sulphate and the solution of sodium chloride.
(ii) Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water)to
produce sodium chloride solution and water.
Solution 3:
i BaCl2(aq) Na2 SO4(aq) BaSO4( s) 2NaCl(aq)
ii NaOH(aq) HCl( aq) NaCl( aq) H2O(l )
, Intext Exercise 2
Question 1:
A solution of a substance ‘X’ is used for white washing.
(i) Name the substance ‘X’ and write its formula.
(ii) Write the reaction of the substance ‘X’ named in (i) above with water.
Solution 1:
(i) The substance ‘X’ is calcium oxide. Its chemical formula is CaO.
(ii) Calcium oxide reacts vigorously with water to form calcium hydroxide (slaked lime).
CaO( s ) H2O(l ) Ca(OH)2( aq)
Calcium oxide (Quick lime) Water Calcium hydroxide (Slaked lime)
Question 2:
Why is the amount of gas collected in one of the test tubes in Activity 1.7 double of the
amount collected in the other? Name this gas.
Solution 2:
Water (H2O) contains two parts hydrogen and one part oxygen. Therefore, the amount of
hydrogen and oxygen produced during electrolysis of water is in a 2:1 ratio. During
electrolysis, since hydrogen goes to one test tube and oxygen goes to another, the amount of
gas collected in one of the test tubes is double of the amount collected in the other.
Intext Exercise 3
Question 1:
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
Solution 1:
When an iron nail is placed in a copper sulphate solution, iron displaces copper from copper
sulphate solution forming iron sulphate, which is green in colour.
Fe( s ) CuSO4( aq)
FeSO4( aq) Cu( s)
Iron Copper sulphate Iron sulphate (Green colur) Copper
(Blue colour)
Therefore, the blue colour of copper sulphate solution fades and green colour appears.
Question 2:
Give an example of a double displacement reaction other than the one given in Activity1.10.
Solution 2:
Sodium carbonate reacts with calcium chloride to form calcium carbonate and
sodiumchloride.
Na 2CO3( aq) CaCl2( aq)
CaCO3( s) 2NaCl( aq)
Sodium carbonate Calcium chloride Calcium carbonate Sodium chloride
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller jitenderkumarjitender. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R645,96. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
82388 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy summaries for 14 years now