Advertisements
Advertisements
प्रश्न
What do you observe when magnesium ribbon is burnt in oxygen?
While burning a magnesium ribbon in air, state two observations of this activity.
Advertisements
उत्तर १
Magnesium ribbon burns with a dazzling white light and produces a white powder, which is magnesium oxide.
Reaction can be represented as:
\[\ce{2Mg + O2 -> \underset{(white powder)}{2MgO}}\]
उत्तर २
- Magnesium produces a dazzling white flame while burning.
- When magnesium burns, it reacts with oxygen to form a white, powdered material.
Notes
Students should refer to the answer according to their questions.
संबंधित प्रश्न
Give one example each of which illustrates the following characteristics of a chemical reaction:
evolution of a gas
Fill in the blank
When a piece of copper is added to silver nitrate solution, it turns ............in colour.
Write chemical equation for the event.
Iron filings are dropped in aqueous solution of copper sulphate.
Write chemical equation for the event.
Electrolysis of alumina is done.
In preparation of Aqua regia hydrochloric acid and _______ acid are mixed.
Which among the following alloys contain mercury as one of its constituents?
A metal M does not liberate hydrogen from acids but reacts with oxygen to give a black colour product. Identify M and black coloured product and also explain the reaction of M with oxygen.
A solution of CuSO4 was kept in an iron pot. After few days the iron pot was found to have a number of holes in it. Explain the reason in terms of reactivity. Write the equation of the reaction involved.
Arrange the following as per the instruction given in the bracket:
Al, K, Mg, Ca (decreasing order of its reactivity)
Three metal samples of magnesium, aluminium and iron were taken and rubbed with sandpaper. These samples were then put separately in test tubes containing dilute hydrochloric acid. Thermometers were also suspended in each test tube so that their bulbs dipped in the acid. The rate of formation of bubbles was observed. The above activity was repeated with dilute nitric acid and the observations were recorded.
Answer the following questions:
(i) When the activity was done with dilute hydrochloric acid, then in which one of the test tubes was the rate of formation of bubbles the fastest and the thermometer showed the highest temperature?
(ii) Which metal did not react with dilute hydrochloric acid? Give reason.
(iii) Why is hydrogen gas not evolved when a metal reacts with dilute nitric acid? Name the ultimate products formed in the reaction.
OR
Name the type of reaction on the basis of which the reactivity of metals is decided. You have two metals X and Y. How would you decide which is more reactive than the other?
