Test Paper X(Science)

TEST PAPER- X(Science) All questions are compulsory. What is a balanced chemical equation? Why should chemical equations be balanced?                                                                                                       1 What does the colour of copper sulphate solution change when an iron nail is dipped in it? Give balanced chemical equation. OR What happens when copper sulphate crystals are heated strongly? Explain with the  help of an equation.                                                                         2   Metal compound A reacts with dil. HCl to produce effervescence. The evolved gas extinguishes a burning candle. Write a balanced chemical equation for the reaction if one of the compounds formed is Calcium chloride.                       1 Name an antacid and an anti-oxidant.                                                                1 Draw electron dot structures of H2S and cylopentane.                           2 Define                                                                                                              4           (a)Calcination                 (b) isomers           (c)Denatured alcohol    (d)Addition reaction Why food cans are coated with tin and not with zinc?                            1 Give IUPAC names of                                                                          1             (a) (b) CH3CH2CHO   Explain the structure of soap.What is soapless soaps.                            3 Give two anomalies of Mendeliev’s Periodic table. What is modern periodic law?                                                                                                                                  2 Element X forms a chloride with formula XCl2, which is a solid with high melting point. X would most likely to be in the same group of periodic table as Na, Mg Al, Si       OR By considering their position in periodic table which one of the following elements would you expect to have maximum metallic character? Ga, Ge, As, Se, Be                                                                               1   What is double displacement reaction? Give an example.                                   2 Explain the term corrosion with example.                                                           1 Name                                                                                                               1       (a) A salt of strong acid an a weak base (b) An ore of mercury. Give the chemical reaction for the formation of P.O.P.                           1 Name a metal found in (a)free state      (b)free as well as combined state OR             Give the outline of formation of MgO.                                                   1