Choose the most appropriate answer for each of the following: Identify the statement which does not describe the property of alkenes :
(A) They are unsaturated hydrocarbons
(B) They decolourise bromine water
(C) They can undergo addition as well as substitution reactions
(D) They undergo combustion with oxygen forming carbon dioxide and water.

Identify a statement that is incorrect about alkanes. (i) They are hydrocarbons. (ii) There is single covalent bond between carbon and hydrogen. (ii) They can undergo addition as well as substitution reactions. (iv) On complete combustion with oxygen, they produce carbon dioxide and water

(i) Which of the following statements is wrong about alkanes ? (A) They are all saturated hydrocarbon. (B) They can undergo addition as well as substitution reaction. (C) They are almost non polar in nature. (D) On complete combustion give out carbon dioxide and water.

Choose the most appropriate answer from the following list of oxides which fit the description. Each answer may be used only once : [SO_(2),SiO_(2),Al_(2)O_(3),MgO,CO,Na_(2)O] An oxide which dissolves in water forming an acid.

Which one of the following statements is correct about the human circulatory system? (A) Blood transports only oxygen and not carbon dioxide. (B) Human heart has five chambers. (C) Valves ensure that the blood does not flow backwards. (D) Both oxygen-rich and oxygen-deficient blood gets mixed in the heart.

Copy and complete the following paragraph using the options given in brackets : Alkenes are a homologous series of (i) ............... (saturated/unsaturated) hydrocarbons characterised by the general formula (ii) ............ ( C_(n)H_(2n+2)// C_(n)H_(2n)) . Alkenes undergo (iii) ................. (addition/substitution) reactions and also undergo (iv) .... (hydrogenation / dehydrogenation) to form alkanes.

Write the balanced chemical equations for the following reactions and identify the type of reaction in each case. (a) Nitrogen gas is treated with hydrogen gas in the presence of a catalyst at 773 K to form ammonia gas. (b) Sodium hydroxide solution is treated with acetic acid to form sodium acetate and water. (c) Ethanol is warmed with ethanoic acid to form ethyl acetate in the presence of concentrated H_2SO_(4) . (d) Ethane is burnt in the presence of oxygen to form carbon dioxide, water and releases heat and light.

Read the following statements w.r.t. bryophytes. (a) They are homosporous. (b) They are first embryophytes. (c) Zygote does not undergo equational division. (d) Water acts as transfer medium for antherozoids to reach the archegonia. (e) In mosses, spores germinate to form filamentous gametophyte. Select the correct option.

An organic compound (A) C_(4)H_(9)Cl on reacting with aqueous KOH gives (B) and on reaction with alcoholic KOH gives (C ), which is also formed on passing the vapours of (B) over the heated copper. The compound (C ) readily decolourises bromine water. Ozonolysis of (C ) gives two compounds (D) and (E ). Compound (D) reacts with NH_(2)OH to give (F) and compound (E ) reacts with NaOH to have an alcohol (G) and sodium salt (H) of an acid. (D) can also be prepared form propyne on treatment with water in the presence of Hg^(2+) and H_(2)SO_(4) . Identify (A) to (H) with proper reasoning.

Write a balanced chemical equation for each of the following reactions and also classify them. (a) Lead acetate solution is treated with dilute hydrochloric acid to form lead chloride and acetic acid solution. (b) A piece of sodium metal is added to absolute ethanol to form sodim ethoxide and hydrogen gas. (c) Iron (III) oxide on heating with carbon monoxide gas reacts to form solid iron and liberates carbon dioxide gas. (d) Hydrogen sulphide gas reacts with oxygen gas to form solid sulphur and liquid water.

Find true and False from the following statements regarding carbohydrates S_(1) : All monosaccharides whether aldoses or ketoses are reducing sugars S_(2) : Bromine water can be used to differentiate between aldoses and ketones S_(3) : A pair of diasteromeric aldoses which differ only in configuration at C-2 are anomers. S_(4) : Osazone formation destroys the configuration of C-2 of an aldose, but does not affect the configuration of the rest of the molecule.