Icse notes

HYDROGEN CHLORIDE – HCl Hydrogen chloride gas is prepared in the following methods. By synthesis or direct combination: H2 + Cl2 2HCl Moisture acts as catalyst. This reaction is not carried out in direct sunlight because it is explosive. Laboratory method – from NaCl and Conc. Sulphuric acid NaCl + H2SO4 NaHSO4 + HCl Conc. 2NaCl + H2SO4 Na2SO4 + HCl Conc. Reactants : Sodium chloride (rock salt) and Conc. H2SO4 Sodium Chloride is preferred because it is cheap and easily available. Conc. H2SO4 is used because it is non-volatile. Conc.HNO3 not preferred because it is a volatile acid. Products : Sodium bisulphate and Hydrogen chloride gas Temperature : less than 2000C If it is more than 2000C Fuel is wasted, the glass apparatus may tend to crack and the product Sodium sulphate form a hard crust which is difficult to remove from the round bottom flask. Precautions : The reactants must be heated slowly –to control the evolution of Hydrogen chloride gas. The lower end o...

 GEOGRAPHY  TRANSPORT STD X 1) Name several means of transport of India.  Ans The present transport system of India comprises of several means of transport including Roadways, Railways, Airways and Waterways.  2) Name the most significant means of transport in India.  Ans Roadways.  ROADWAYS 1)State the significance of Roadways in India OR Why are Roadways gaining more importance that many other means of transport? Ans The following are the reasons for the gaining significance of roadways: Cost: Roads are cheaper than all other modes of transport on land i.e. railways and airways. Easier Construction: Railways can be easily constructed along hilly terrain, rugged surfaces, remote areas, steep slopes etc. where other forms of transport would be difficult to construct. Door to Door Service: Only Roadways provide door-to-door services, thus making transportation very convenient. Faster means of transport: Roads are a faster means especiall...

                                       LITERATURE IN ENGLISH                                 Class: 9 and 10 THE COLD WITHIN  - James Patrick Kinney I. Read the extract given below and answer the questions that follow: Their dying fire in need of logs, But the first one held hers back, For, of the faces round the fire, She noticed one was black. What is the background against which the poem is narrated? The poem is narrated against the background of six humans being trapped together by chance in bleak and bitter cold. Comment on the form and tone of the poem. The Cold Within is written in the form of a narrative poem. This form of poetry tells a story. The tone of the poem is melancholic. Discuss the literal and metaphorical meaning of the line-‘Their dying fire in need of logs’. ...