ECAT Pre Engineering MCQ Test With Answer for Chemistry Full Book

The value of R (Rydberg's constant) is _______ m-1

• 1.0974 x 107 A
• 1.0842 x 107 B
• 1.082 x 10-7 C
• Both a and b D

Which one of the following reagents will distinguish between C₆H₅CHO and C₆H₅COCH₃

• Aqueous bromine A
• Phosphorus pentachloride B
• 2, 4 DNPH C
• Tollen's reagent D

Alkali metals have electrons in s-orbital:

• one A
• two B
• three C
• Four D

Which of the following is strangest reducing agent.

• Cl- A
• K+ B
• Ar C
• Ca+2 D

During dehydration of alcohols to alkenes by heating with conc. H₂SO₄, the initial step is

• Formation of an ester A
• Protonation of alcohol molecule B
• Formation of carbocation C
• Elimination of water D

The general formula for alkenes is

• C_nH_2n+1 A
• C_nH_2n+2 B
• C_nH_2n C
• C_nH_2n-2 D

Which of the following waste material is not recycled for use again

• Paper A
• Plastic B
• Hides of animals C
• Glass D

• Le-chatlier's principle A
• Only adding catalyst B
• Decreasing pressure C
• Decreasing temperature D

Which one of the following compounds does not have the empirical formula CH₂O?

• Ethanoic acid, CH₃CO₂H A
• Ethanol, CH₃CH₂OH B
• Glucose, C₆H₁₂O₆ C
• Methanal, HCHO D

Solvay process is used in the manufacture of

• Na₂CO₃ A
• NaHCO₃ B
• CaCl₂ C
• All D

_{Which compound is the most reactvie one:}

• benzene A
• ethene B
• ethane C
• ethyne D

Cyclohexane can be converted not benzene in the presence of

• Pt at 100°C A
• Pt at 250°C B
• Pd at room temperature C
• Pt at room temperature D

Urea has concentration when prepared before prlilling:

• 100% A
• 99.7% B
• 82% C
• 46% D

The fractions obtained from fractional distillation of petroleum are placed in increasing order of their boiling points. Which order is correct

• Natural gas, petroleum ether, gasoline kerosene A
• Petroleum ether, kerosene, natural gas, petroleum ether B
• Gasoline, kerosene, natural gas, petroleum ether C
• Kerosene, gasoline, petroleum ether, natural gas D

Cooling happens under the Joule Thomson Effect due to sudden

• Contraction A
• Absorption B
• Expansion C
• All of above D

Which is possible in ethers?

• Reactivity high A
• Oxidation and reduction B
• Reactivity towards bases C
• Towards acids D

The number of moles of NH₄CI dissolved in 500 cm³of its 15%, W/N solution is

• 1 mole A
• 1.4 mole B
• 2.0 mole C
• 2.4 mole D

Chief ore of aluminium is:

• Na₃AIF₆ A
• Al₂O₃.2H₂O B
• Al₂O₃ C
• Al₂O₃ .H₂O D

Content of carbon in steel is:

• 0.12 to 0.25% A
• 0.25% to 2.5% B
• 3.0 to 3.5% C
• 4.0 to 4.5% D

If the radius of first Bohr orbit be a_o, then the radius of third Bohr orbit would be

• 3 x a_o A
• 6 x a_o B
• 9 x a_o C
• 1/2 x a_o D

Aromatic aldehydes undergo disproportionation in presence of sodium or potassium hydroxide to give corresponding alcohol and acid. The reaction is known as

• Wurtz reaction A
• Cannizzaro reaction B
• Friedel Craft reaction C
• Claisen reaction D

Steel is manufactured by open Hearth process from.

• Wrought iron A
• Cast iron B
• Steel scrap C
• All of the above D

The periodic table gives basic framework to study the periodic.

• Elements only A
• Compounds only B
• Elements and their compounds C
• Elements and their inorganic D

If the standard electrode potential of CU²⁺/Cu electrode is 0.34 V, what is the electrode potential of 0.01 M concentration of Cu²⁺? (T=298)

• 0.399 V A
• 0.281 V B
• 0.222 V C
• 0.176 V D

Law of triads was given by:

• Al-Razi A
• Dobriener B
• Newland C
• Mendeleev D

Cotton has cellulose in it:

• 96% A
• 97% B
• 98% C
• 99% D

In the rate equation when the concentration of reactants are unity, then rate is equal to

• Instantaneous rate A
• Average rate B
• Active mass of products C
• Specific rate constant D

Sodium is never found free in nature because of its

• Chemical reactivity A
• Small ionic size B
• Small atomic volume C
• None of these D

Which of the following element is responsible for oxidation of water to O₂in biological process?

• Fe A
• Mn B
• Cu C
• Mo D

In Friedal-Craft's alkylation besides AlCl3 the other reactants are

• C6H6 + NH3 A
• C6H6 + NH4 B
• C6H6 + CH3Cl C
• C6H6 + CH3COCl D