class 10 complete science Quizz

When crystals of lead nitrate are heated strongly in a dry test tube

• (a) crystals immediately melt

• (b) a brown residue is left

• (c) white fumes appear in the test tube

• (d) a yellow residue is left

A dilute ferrous sulphate solution was gradually added to the beaker containing acidified permanganate solution. The light purple colour of the solution fades and finally disappears. Which of the following is the correct explanation for the observation? [NCERT Exemplar]

• (a) KMnO4 is an oxidising agent, it oxidises FeSO4

• (b) FeSO4 acts as an oxidising agent and oxidises KMnO4

• (c) The colour disappears due to dilution, no reaction is involved

• (d) KMnO4 is an unstable compound and decomposes in the presence of FeSO4 to a colourless compound

A solution reacts with crushed-egg shells to give a gas that turns lime water milky. The solution contains

• (a) NaCl

• (b) HCl

• (c) LiCl

• (d) KCl

10 mL of a solution of NaOH is found to be completely neutralised by 8 mL of a given solution of HC1. If we take 20 mL of the same solution of NaOH, the amount of HC1 solution (the same solution as before) required to neutralise it will be

• (a) 4 mL

• (b) 8 mL

• (c) 12 mL

• (d) 16 mL

Which of the following pairs will give displacement reactions ?

• (a) NaCl solution and copper metal.

• (b) MgCl2 solution and aluminium metal.

• (c) FeSO4 solution and silver metal.

• (d) AgNO3 solution and copper metal.

Buckminster fullerene is an allotropic form of [NCERT Exemplar]

• (a) phosphorus

• (b) sulphur

• (c) carbon

• (d) tin

The hetero atoms present in

CH3 – CH2 – O – CH2 – CH2Cl are [NCERT Exemplar]

(i) oxygen

(ii) carbon

(iii) hydrogen

(iv) chlorine

• (a) (i) and (ii)

• (b) (ii) and (iii)

• (c) (iii) and (iv)

• (d) (i) and (iv)

Which of the following statements is not a correct statement about the trends wlien going from left to right across the periods of Periodic Table.

• (a) The elements become less metallic in nature.

• (b) The number of valence electrons increases.

• (c) The atoms lose their electrons more easily.

• (d) The oxides become more acidic.

The xylem in plants are responsible for

• (i) transport of water

• (ii) transport of food

• (iii) transport of amino acids

• (iv) transport of oxygen

Offsprings formed by asexual method of reproduction have greater similarity among themselves because [NCERT Exemplar]

I. asexual reproduction involves only one parent.

II. asexual reproduction does not involve gametes.

III. asexual reproduction occurs before sexual reproduction.

IV. asexual reproduction occurs after sexual reproduction.

• (a) I and II

• (b) I and III

• (c) II and IV

• (d) III and IV