English Medium इयत्ता १० - CBSE Question Bank Solutions

Explain why, when a copper object remains in damp air for a considerable time, a green coating is formed on its surface. What is this process known as?

Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken.

Name a common metal which is highly resistant to corrosion.

A common metal which is highly resistant to corrosion is ______.

In stainless steel alloy, iron metal is mixed with ______.

If copper is kept exposed to damp air for a considerable time, it gets a green coating on its surface. This is due to the formation of ______.

Brass is an alloy of ______.

No chemical reaction takes place when granules of a rusty-brown solid A are mixed with the powder of another solid B. However, when the mixture is heated, a reaction takes place between its components. One of the products C is a metal and settles down in the molten state while the other product D floats over it. It was observed that the reaction is highly exothermic.

1. What could the solids A and B be?
2. What are the products C and D most likely to be?
3. Write the chemical equation for the reaction between A and B leading to the formation of C and D. Mention the physical states of all the reactants and products in this equation and indicate the heat change which takes place.
4. What is the special name of such a reaction? State one use of such a reaction.
5. Name any two types of chemical reactions under which the above reaction can be classified.

A metal X which is resistant to corrosion is produced by the electrolysis of its molten oxide whereas another metal Y which is also resistant to corrosion is produced by the reduction of its oxide with carbon. Metal X can be used in powder form in thermite welding whereas metal Y is used in making cathodes of ordinary dry cells.

1. Name the metals X and Y.
2. Which of the two metals is more reactive: X or Y?
3. Name one ore or metal X. Also write its chemical formula.
4. Name one ore of metal Y. Also write its chemical formula.
5. Name one alloy of metal X and one alloy of metal Y.

Four metals P, Q, R and S are all obtained by the reduction of their oxides with carbon. Metal P is used to form a thin layer over the sheets of metal S to prevent its corrosion. Metal Q is used for electroplating tiffin boxes made of metal S whereas metal R is used in making car batteries. Metals Q and R form an alloy called solder. What are metals P, Q, R and S? How have you arrived at this conclusion?

Bronze is an alloy of ______.

In the following diagram, the correctly marked angles are

(A) All
(B) Only ∠i and ∠A
(C) ∠i, ∠r and ∠A
(D) ∠i, ∠A and ∠D

In an experiment to trace the path of a ray of light through a triangular glass prism, a student would observe that the emergent ray

(a) is parallel to the incident ray.

(b) is along the same direction of incident ray.

(c) gets deviated and bends towards the thinner part of the prism.

(d) gets deviated and bends towards the thicker part (base) of the prism.

In which of the following four diagrams is the correct path of a ray of light passing through a glass prism shown ?

While performing the experiment to trace the path of a ray of light passing through a glass prism, four students marked the incident ray and the emergent ray in their diagrams in the manner shown below. 

(A) I

(B) II

(C) III

(D) IV

In an experiment to trace the path of a ray of light through a glass prism for different values of angle of incidence a student would find that the emergent ray: 

(A) is parallel to the incident ray

(B) perpendicular to the incident ray

(C) is parallel to the refracted ray

(D) bends at an angle to the direction of incident ray

When we place a glass prism in the path of a narrow beam of white light a spectrum is obtained. What happens when a second identical prism is placed in an inverted position with respect to the first prism? Draw a labelled ray diagram to illustrate it.

Draw a labeled ray diagram to illustrate the dispersion of a narrow beam of white light when it passes through a glass prism.

No chemical reaction takes place when granules of a solid, A, are mixed with the powder of another solid, B. However when the mixture is heated, a reaction takes place between its components. One of the products, C, is a metal and settles down in the molten state while the other product, D, floats over it. It was observed that the reaction is highly exothermic.

(i) Based on the given information make an assumption about A and B and write a chemical equation for the chemical reaction indicating the conditions of reaction, physical state of reactants and products and thermal status of reaction.

(ii) Mention any two types of reactions under which above chemical reaction can be classified.

A glass prism is able to produce the spectrum when white light passes through it, but a glass slab doesn’t produce any spectrum. Explain why it is so.