CLASS -10
CHEMISTRY WORKSHEET.

  CHEMISTRY                                                                                                                                                                                                                                                               30M    

1.       Name two organic acids.                                                                                                                 1M

2.       Which of the following reactions is not correct?

         Zn +CuSO₄ → ZnSO₄+ Cu

Ag +Cu (NO₃)₂ → Ag(NO₃)₂ +Cu

Fe+ CuSO₄ → FeSO₄+ Cu

2Mg + 2HCl→ MgCl₂+ H₂   

                                                                                                                                                         1M     

3.       Washing soda has the formula

Na2 CO3.7 H 2O 

Na2 CO3.10 H2 O

Na2 CO3.2 H 2O

Na2 CO3     

                                                                                                                                                                   1M

4.       Which of the following is evolved when Na2CO3 is heated?

a.       (a) CO2      (b) CO         (c) O2          (d) No                                                                                    1M

5.        Why does not an acid show any acidic behavior in the absence of water?        

                  2M

6.       Fresh milk has a pH of 6. What will be the PH value if milk changes into a curd Justify.           2M

7.       A housewife found that the cake prepared by her is hard and small in size. Which ingredient has she forgotten to add that would have made the cake fluffy. Give reason.  

                     2M

8.       What is water of crystallization. Name two hydrated salts.                                                        2M

9.       2. “Write the balanced chemical equations for the following and identify the type of reaction in each case:                                                                                                                                            3M

Barium chloride (aq) + potassium sulphate (aq) ---- Barium sulphate (s) + Potassium chloride (aq)

Zinc carbonate (s) ------- Zinc oxide (s) + Carbon dioxide (g)

Magnesium (s) + Hydrochloric acid (aq) ------- Magnesium chloride (aq) + Hydrogen(g)

10.   .       1 Write short notes with examples on following:

a.       Corrosion

b.   rancidity                                                                                                                                   3M                              

11.   18.In the reaction MnO₂ +4HCl--------- MnCl₂ + 2H₂O +Cl₂

a.       Name the substance oxidised.

b.      Name the oxidising agent.

c.       Name the reducing agent and the substance reduced. 

                                   3M

12.   Give one example each of

Thermal decomposition

Electrolytic decomposition

Photo decomposition                                                                                                                       3M

13.   How is plaster of Paris chemically different from gypsum? How may these be inter converted? Write one use of plaster of Paris?                                                                                                  3M

14.   Why does a solution of sodium chloride conduct electricity while solid sodium chloride does  not?                                                                                                                                                              3M

With the help of chemical equations show that Al203 is an amphoteric oxide?

Shoe the formation of

NaCl , Na₂O, MgCl₂,AlCl₃