Science

Q.

Samples of four metals A, B, C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows.

Metal	Iron (II) sulphate	Cooper (II) sulphate	Zinc sulphate	Silver nitrate
A.	No reaction	Displacement
B.	Displacement		No reaction
C.	No reaction	No reaction	No reaction	Displacement
D.	No reaction	No reaction	No reaction	No reaction

Use the Table above to answer the following questions about metals A, B, C and D.

(i) Which is the most reactive metal?

(ii) What would you observe if B is added to a solution of copper (II) sulphate?

(iii) Arrange the metals A, B, C and D in the order of decreasing reactivity.

Q. Write the IUPAC names of the following structural formulae.

a. CH3-CH2-CH2-CH3	b. CH3-CHOH-CH3
c. CH3-CH2-COOH	d. CH3-CH2-NH2
e. CH3-CHO	f. CH3-CO-CH2-CH3

Q. Write down the electronic configuration of the following elements from the given atomic numbers. Answer the following question with explanation.
a. ₃Li, ₁₄He, ₁₁Na, ₁₅P Which of these elements belong to be period 3?
b. ₁H, ₇N, ₂₀Ca, ₁₆S, ₄Be, ₁₈Ar Which of these elements belong tot he second group?
c. ₇N, ₆C, ₈O, ₅B, ₁₃Al Which is the most electronegative element among these?
d. ₄Be, ₆C, ₈O, ₅B, ₁₃Al Which is the most electropositive element among these?
e. ₁₁Na, ₁₅P, ₁₇Cl, ₁₄Si, ₁₂Mg Which of these has largest atoms?
f. ₁₉K, ₃Li, ₁₁Na, ₄Be Which of these atoms has smallest atomic radius?
g. ₁₃Al, ₁₄Si, ₁₁Na, ₁₂Mg, ₁₆S Which of the above elements has the highest metallic character?
h. ₆C, ₃Li, ₉F, ₇N, ₈O Which of the above elements has the highest nonmetallic character?

Q. Define heredity. Explain the mechanism of hereditary changes.

Q.

What criteria do we use to decide whether something is alive?

Q.

Arrange the following metals in the decreasing order of chemical reactivity, Cu, Mg, Fe, Na, Ca, Zn.

Q. Explain the working of an astronomical telescope using refraction of light.

Q. (a) What is meant by chemical reaction? Explain with the help of an example.
(b) Give one example each of a chemical reaction characterised by:
(i) evolution of a gas
(ii) change in colour
(iii) formation of a precipitate
(iv) change in temperature
(v) change in state.

Q.

What is the role of the acid in our stomach?

Q.

Write a short note on:

Darwin’s theory of evolution.

Q. Translate the following statements into chemical equations and then balance them:

Q. Identify the type of the following reaction of carbon compounds.
a. CH₃ -CH₂ -CH₂-OH → CH₃ -CH₂ -COOH
b. CH₃ -CH₂ -CH₃ → 3CO₂ + 4H₂O
c. CH₃ -CH = CH -CH₃ + Br₂ → CH₃ -CHBr - CHBr -CH₃
d. CH₃ -CH₃ + Cl₂ → CH₃ -CH₂ -Cl + HCl
e. CH₃ -CH₂ -CH₂ -CH₂ -OH → CH₃ -CH₂ -CH=CH₂ + H₂O
f. CH₃ -CH₂ -COOH + NaOH → CH₃ -CH₂ -COO - Na⁺ + H₂O
g. CH₃ -COOH + CH₃ -OH → CH₃ -COO- CH₃ + H₂O

Q.

Answer the following questions

What is the fundamental duty of each citizen regarding environment?

Q.

What is the function of digestive enzymes?

Q.

What is an alloy? Give two examples with their chemical composition.

Q.

What are the differences between autotrophic nutrition and heterotrophic nutrition?

Q. Read the following statements and justify same in your own words with the help of suitable examples.
a. Human evolution began approximately 7 crore years ago.
b. Geographical and reproductive isolation of organisms gradually leads to speciation.
c. Study of fossils is an important aspect of study of evolution.
d. There is evidences of fetal science among chordates.

Q. Which fuel is used in thermal power plant? What are the problems associated with this type of power generation?

Q. Write the balanced chemical equation for the following and identify the type of reaction in each case:

Q.

Answer the following questions

What is recycling? Give one example.

Q. Explain the following temperature vs time graph.

Q. What is a balanced chemical equation? Why should chemical equations be balanced?

Q.

The process of digestion of food in humans begins in:
(a) stomach
(b) food pipe
(c) mouth
(d) small intestine

Q.

How are fats digested in our bodies? Where does this process take place?

Q. (a) What are heterotrophs? Give one example of heterotrophs.
(b) What is the difference between autotrophic nutrition and heterotrophic nutrition?

Q. A place in desert where water is found is known as .

1. oasis
2. ocean
3. rain
4. pool

Q. Identify the endothermic and exothermic reaction.
a. HCl + NaOH → NaCl + H₂O + heat
b. $2{\mathrm{KClO}}_3\left(\mathrm{s}\right)\stackrel{∆}{\to }2\mathrm{KCl}\left(\mathrm{s}\right)+3{\mathrm{O}}_2\uparrow$
c. CaO + H₂O → Ca(OH)₂ + heat
d. $Ca{\mathrm{CO}}_3\left(\mathrm{s}\right)\stackrel{∆}{\to }CaO\left(\mathrm{s}\right)+{\mathrm{CO}}_2\uparrow$

Q. Write the balanced chemical equations for the following reactions:
(a) $\mathrm{Calcium}hydroxide+\mathrm{Carbon}dioxide\underset{}{\to }\mathrm{Calcium}\mathrm{carbonate}+\mathrm{Water}$
(b) $\mathrm{Aluminium}+\mathrm{Copper}\mathrm{chloride}\underset{}{\to }\mathrm{Aluminium}\mathrm{chloride}+\mathrm{Copper}$

Q. Explain with diagram step-by-step energy conversion in
a. Thermal power plant
b. Nuclear Power Plant.
c. Solar thermal power plant
d. Hydroelectric power plant

Q. How is oxygen and carbon dioxide is transported in human being