ASSIGNMENT : FIRST TERM (2012-2013)SUBJECT: CHEMISTRY:CHAPTER: METALS AND NON- METALS
ASSIGNMENT : FIRST TERM (2012-2013) X - CHEMISTRY CHAPTER: ACIDS AND BASES Max Marks: 25 |
A. Very short answer questions: (1 mark each) (1x 6= 6marks) |
1. A calcium compound which is yellowish white powder is used as a disinfectant and also in textile industry. Name the compound. Which gas is released when this compound is left exposed to air ? |
2. Which element is common to all acids ? |
3. What is common name of water soluble bases ? |
4. Write the neutralization reaction between acids and bases in terms of the ions involved. |
5. Two solutions A and B have pH values 3.0 and 9.5 respectively. Which of these will turn litmus solution from blue to red and which will turn phenolphthalein from colourless to pink. |
6. Name the raw material used for the production of caustic soda. |
B. Short answer questions: (2 marks each) (2x5=10) |
1. State the chemical property in each case on which the following uses of baking soda are based: |
a. as an antacid |
b. as a constituent of baking powder |
2. Take 5 ml of hydrochloric acid in boiling tube or a conical flask. Add few pieces of zinc granules to it. |
a. What do you observe on the surface of zinc granules? |
b. Name the gas evolved. |
c. What happens when the above gas is passed through soap solution ? |
d. What happens when a burning candle is brought near the gas filled bubble ? |
3. A housewife found that the cake prepared by her is hard and small in size. Which ingradient has she forgotten to add that would have made the cake fluffy. Give reason. |
4. Crystals of a substance changed their colour on heating in a closed vessel but regained it after sometime when allowed to cool down. Name one such substance. Explain the phenomenon involved. |
5. How is plaster of paris prepared ? Write the equation of the reaction involved. |
C. Short answer questions: (3 marks each)(3x 3= 9) |
1. A compound X of sodium forms a white powder. It is a constituent of baking powder and is used in some antacid prescriptions. When heated, X gives out a gas and steam. The gas forms a white precipitate with lime water. Write the chemical formula and name of X and the chemical equation for its decomposition on heating. What is its role in baking powder and in antacids. |
2. What is the role of pH in our daily life ? |
3. What happens when: |
(a) solid sodium hydrogen carbonate is heated |
(b) chlorine gas is passed through dry slaked lime |
(C) gypsum is heated to a temperature of 373 K. |
Comments
Post a Comment