Chemistry · Class 10 CBSE
A student accidentally drops an iron hammer and a piece of sulphur. The hammer does not break, but the sulphur shatters into pieces. Which property of metals is demonstrated?
A jewellery maker chooses gold instead of sodium for making ornaments. What is the most appropriate reason?
A student places iron nails in copper sulphate solution. After some time, the blue colour fades and a reddish-brown coating appears on the nails. What is the reason?
Which metal is stored under kerosene to prevent it from reacting with air and moisture?
A metal oxide is heated with carbon, producing the pure metal. This process is an example of:
A student connects a copper wire and a graphite rod in an electric circuit. Both conduct electricity. What is the best explanation?
Why are cooking utensils generally made of aluminium instead of calcium?
A student observes that zinc reacts with dilute hydrochloric acid, but copper does not. What conclusion can be drawn?
A silver spoon becomes black after being exposed to air for several weeks. Which process is responsible?
An engineer wants to build an electric transmission line. Which property of metals is most important for this purpose?
Type your answer in your own words. On submit, our AI examiner grades each answer, gives feedback, and shows the model answer.
Why are metals generally good conductors of electricity, whereas most non-metals are not?
2 marksDifferentiate between corrosion and rusting with one example of each.
2 marksWhy are ionic compounds generally poor conductors of electricity in the solid state but good conductors in the molten or aqueous state?
2 marksWhy are aluminium wires commonly used for overhead power transmission instead of iron wires? Give any two reasons.
2 marksA student accidentally leaves an iron bicycle in the rain for several days. Suggest two methods to prevent rusting and explain how they work.
2 marksExplain the reactivity series of metals. Using suitable examples, describe: - Why some metals displace others from salt solutions. - Why highly reactive metals are extracted using electrolysis. - Why less reactive metals can be obtained by reduction with carbon.
5 marksDescribe the formation of ionic compounds using the example of sodium chloride. In your answer, explain: - Electron transfer - Formation of ions - Ionic bond - Three important properties of ionic compounds
5 marksCase study: A student conducted three experiments: - Experiment 1: An iron nail was placed in copper sulphate solution. - Experiment 2: A copper strip was placed in zinc sulphate solution. - Experiment 3: Sodium metal was carefully added to water under the teacher\'s supervision. The student observed different results in each experiment. Answer the following questions: (a) Which experiment demonstrates a displacement reaction? Explain why it occurs.
1 markCase study: A student conducted three experiments: - Experiment 1: An iron nail was placed in copper sulphate solution. - Experiment 2: A copper strip was placed in zinc sulphate solution. - Experiment 3: Sodium metal was carefully added to water under the teacher\'s supervision. The student observed different results in each experiment. Answer the following questions: (b) Why does copper fail to react with zinc sulphate solution?
1 markCase study: A student conducted three experiments: - Experiment 1: An iron nail was placed in copper sulphate solution. - Experiment 2: A copper strip was placed in zinc sulphate solution. - Experiment 3: Sodium metal was carefully added to water under the teacher\'s supervision. The student observed different results in each experiment. Answer the following questions: (c) Why must sodium be handled very carefully during laboratory experiments?
1 markCase study: A student conducted three experiments: - Experiment 1: An iron nail was placed in copper sulphate solution. - Experiment 2: A copper strip was placed in zinc sulphate solution. - Experiment 3: Sodium metal was carefully added to water under the teacher\'s supervision. The student observed different results in each experiment. Answer the following questions: (d) Based on these observations, what conclusion can be drawn about the relative reactivity of sodium, iron, copper, and zinc?
1 mark