Chemistry Worksheet - Class 9

Transcription

1 Chemistry Worksheet - Class 9 Chapter: The periodic table, Language of Chemistry, Hydrogen One word answer: A. B. i) The longest period ii) Special name given to group 17 elements. iii) Noble gas having duplet configuration of electrons iv) Formula of hydride of a halogen in the period3 v) Halogen which is liquid at room temperature. vi) Halogen which forms violet vapours on heating. vii) An alkali metal stored under kerosene. viii) An element which has four valence electrons and possess the ability to catenate. ix) Who gave modern periodic table. x) Modern Periodic table is based on which fundamental property. xi) Give an example of Dobereiner s triad. xii) Name the elements in period 1. xiii) Name the groups: Group 1, group 2, group 18,group 17. i) What is the cause of periodicity? ii) What is Modern Periodic Law? iii) Write 3 contributions made by Mendeleev? iv) Write three defects of Mendeleev s Periodic table. v) What is Dobereiner s triad? Give one example. vi) Explain Newland s Law of Octaves with suitable example. vii) Explain why reducing power of elements increases as one goes down a group? viii) How many elements are there in 1 st,2 nd and 3 rd period of the periodic table? ix) The electronic configuration of an element T is 2,8,7. a) What is the group number of T? b) What is the period number of T? c) What is the valency of T? d) Is T a metal or a non-metal? e) How many valence electrons are there in an atom of T?

2 C. An element Z is in second period and group 16 of the periodic table. a) Is it a metal or non-metal? b) What is the number of valence electrons in its atom? c) What is its valency? d) What will be the formula of the compound of Z with sodium? e) What is the name of the element? iii) An element A belongs to the third period and group 1 of the periodic table. Find out : a) The number of valence electrons in its atom. b) Valency of the element c) Metal or non-metal d) Name of the family to which this element belongs and e) Name of the element. iv) An element X belongs to the group 2 and another element Y belongs to group 15 of the periodic table. a) What is the number of valence electrons in X? b) What is the valency of X? c) What is the number of valence electrons in Y? d) What is the valency of Y? x o x x The language of chemistry Q1)Give the valency and the formula of the following radicals: a)chlorate b)oxalate c)zincate d)silicate e)phosphate f)nitride g)cupric Q2.Write the valency of: i) nitrogen in N 2 O ii) Sulphur in SF 6 iii)fluorine in CaF 2 iv)manganese in KMnO 4

3 Q3.Write the chemical formulae of the following compounds: i) Barium bicarbonate ii) Ferric phosphate iii) Silver(II) sulphide i) Ammonium acetate v) Lead bromide. Q4.Write the name of the following molecular formula: i) K 2 MnO 4 ii) Al 2 (CO 3 ) 3 iii) (CH 3 COO) 2Pb iv) Na 2 SiO 3 iv) MgSO 4 Q5. Write the formulae and valency of the following radicals: i) Aluminate ii) Nitride iii) Phosphate iv) Peroxide v) Sulphite. Q6. a) An element X is trivalent.state the formula of its i) sulphate ii) hydroxide b) Why should an equation be balanced? Q7. A metal M forms a carbonate having the following formula M 2 (CO 3 ) 3. i) What is the valency of M? ii) What will be the formula of fluoride of M? Q8. Define i) Radical ii) Variable valency iii) Chemical formula iv) Balanced equation Q9. CaCO 3 + 2HCl (dil) CaCl 2 +H 2 O +CO 2 (g) i) State the information provided by the above chemical equation. ii) State the information not conveyed by the above chemical equation. Q10.Balance the following equations : i) Pb 3 O 4 + HCl PbCl 2 +H 2 O + Cl 2 ii) NH 3 +O NO + H 2 O iii) ZnS + O ZnO +SO 2 iv) S + H 2 SO 4 (Conc.) SO 2 + H 2 O v) KOH + Cl KCl + KClO +H 2 O

4 vi) Cu + H 2 SO Cu SO 4 + H SO 2 vii) C + HNO CO 2 + NO 2 + SO 2 viii) H 2 S + SO S + H 2 O ix) Fe + H 2 O Fe 3 O 4 + H 2 x) NH 3 + O NO + H 2 O Q11. Fill in the blanks: i) Positive radical are called radicals. ii) iii) iv) Chloride, bromide and Iodide are radical radical is a basic radical although it is not a metal. The formula of magnesium nitride is v) Formulae are made by method. Q12. A. Write the following answers in pairs : Name of the compound Formula i) Sodium hypochlorite NaNO 2 ii) Sodium Chlorate NaClO iii) Sodium nitrite NaHSO 4 iv) Sodium silicate NaClO 3 v)sodium bisulphate Na 2 SiO 3 B. Define 1)Valency 2) Radicals x o x

5 HYDROGEN Q1. Answer the following questions related to laboratory preparation of Hydrogen gas: i) Name the reactants used. ii) Give the balanced chemical equation. iii) How is the gas collected and Why? iv) Why dilute nitric acid is not preferred as the reactant acid? v) Why lead cannot be used in the preparation of hydrogen using dilute acids? Q2. i) Name the two metals which will displace hydrogen from strong caustic alkalies.write Chemical equation in support of your answer. ii) How is hydrogen prepared industrially by Bosch process. iii) How are unreacted gases separated out in Bosch process in the manufacture of hydrogen. Q3. i) Name two metals which react with cold water to form hydrogen.write the balanced chemical equations. ii) Name one metal which cannot be used for the preparation of hydrogen using dilute acids. iii) Why is hydrogen placed in both group 1 and 17. iv) Potassium and Sodium are not used to react with dilute HCl in the lab.preparation of hydrogen. V) Magnesium reacts with very dilute nitric acid at low temperature liberating hydrogen. vi)two jars of Hydrogen are collected one burns quietly and the other does not.justify. Q4. Name two metals which react with steam and displace hydrogen.write the balanced chemical equations. Q5. i)name the chemicals used in the purification of hydrogen gas prepared from granulated zinc. Q6.Name the following: i) The metal which reacts fastest with cold water. ii) Name the metal which does not react with cold water,but reacts with boiling hot water very slowly.

6 iii) Name the metal which on heating reacts with steam,but reaction is reversible. iv) Name a metal which reacts explosively with dilute HCl. iv) Name a metals which reacts vigourously with dilute HCl. v) Name a metal which does not react with water or dilute HCl. Q7. I) How will you convert Aluminium to sodium aluminate?give a balanced reaction for the same. ii)why is granulated zinc preferred in the preparation of Hydrogen gas? iii)hydrogen reduces oxides of mwtals.give three examples,with balanced equations,in support of this statement. iv) How would you obtain hydrogen using a) dil acid b) conc.solution of an alkali? vi) Name the gas which burns in air or oxygen forming water. vii) State the products formed,when steam is passed over red hot iron. viii) What do you observe when a piece of sodium is dropped into cold ix) water? Describe an experiment to show that hydrogen on burning forms water. x) State one property of hydrogen: a) That makes it useful in meteorological balloon. b) Due to which it is no longer used in weather balloons. c) That makes it a good fuel. Q8.Name the products and balance the equations: i) Na + H 2 O ii) K+ H 2 O iii) Fe + H 2 O iv) Mg + HCl v) Al + HCl vi) Zn + H 2 SO vii) Fe 3 O 4 + H viii) Al + NaOH + H 2 O ix) Ca + H 2 O x) C + H 2 O (steam) x o x