A catalyst is a substance which (a) stops a chemical reaction (b) helps initiate a reaction (c) increases the speed of a reaction (d) decreases the speed of a reaction

A catalyst is a substance which (a) stops a chemical reaction (b) helps initiate a reaction (c) increases the speed of a reaction (d) decreases the speed of a reaction
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Catalyst is a substance, which __________ chemical reaction. (A) Increases the speed of a (B) Decreases the speed of a (C) Can either increase or decrease the speed of a (D) Alters the value of equilibrium constant in a reversible

Description : Catalyst is a substance, which __________ chemical reaction. (A) Increases the speed of a (B) Decreases the speed of a (C) Can either increase or decrease the speed of a (D) Alters the value of equilibrium constant in a reversible

Last Answer : (C) Can either increase or decrease the speed of a

Catalyst is a substance which (1) increases the rate of the reaction (2) decreases the rate of reaction (3) has no action on the rate of the reaction (4) None of these

Description : Catalyst is a substance which (1) increases the rate of the reaction (2) decreases the rate of reaction (3) has no action on the rate of the reaction (4) None of these

Last Answer : None of these

A catalyst in a chemical reaction __________ free energy change in the reaction. (A) Increases (B) Decreases (C) Either (A) or (B); depends on the type of catalyst (D) Neither (A) nor (B)

Description : A catalyst in a chemical reaction __________ free energy change in the reaction. (A) Increases (B) Decreases (C) Either (A) or (B); depends on the type of catalyst (D) Neither (A) nor (B)

Last Answer : (C) Either (A) or (B); depends on the type of catalyst

When a catalyst increases the rate of chemical reaction, the rate constant (A) Decreases (B) Increases (C) Remain constant (D) Become infinite

Description : When a catalyst increases the rate of chemical reaction, the rate constant (A) Decreases (B) Increases (C) Remain constant (D) Become infinite

Last Answer : (B) Increases

A catalyst in a chemical reaction (A) Decreases the activation energy (B) Alters the reaction mechanism (C) Increases the frequency of collisions of reacting species (D) All (A), (B) and (C)

Description : A catalyst in a chemical reaction (A) Decreases the activation energy (B) Alters the reaction mechanism (C) Increases the frequency of collisions of reacting species (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

The equilibrium constant of a catalytic chemical reaction __________ due to the presence of a catalyst. (A) Increases (B) Decreases (C) Remain unaffected (D) Unpredictable from the data

Description : The equilibrium constant of a catalytic chemical reaction __________ due to the presence of a catalyst. (A) Increases (B) Decreases (C) Remain unaffected (D) Unpredictable from the data

Last Answer : (C) Remain unaffected

The equilibrium constant of chemical reaction __________ in the presence of catalyst. (A) Increases (B) Decreases (C) Remain unaffected (D) Can either increase or decrease (depends on the type of catalyst)

Description : The equilibrium constant of chemical reaction __________ in the presence of catalyst. (A) Increases (B) Decreases (C) Remain unaffected (D) Can either increase or decrease (depends on the type of catalyst)

Last Answer : (C) Remain unaffected

(4) None of these Explanation: Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations. Catalysts that speed the reaction are called positive catalysts.

Description : (4) None of these Explanation: Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that ... may participate in multiple chemical transformations. Catalysts that speed the reaction are called positive catalysts.

Last Answer : Table salt gets moist during rainy season because – (1) sodium chloride is hygroscopic (2) sodium chloride is deliquescent (3) sodium chloride contains some quantity of sodium iodide (4) sodium chloride contains hygroscopic impurities like magnesium chloride

A catalyst is said to be a negative catalyst, if it (A) Retards the rate of reaction (B) Reduces the value of equilibrium constant (C) Does not initiate the reaction (D) All (A), (B) and (C)

Description : A catalyst is said to be a negative catalyst, if it (A) Retards the rate of reaction (B) Reduces the value of equilibrium constant (C) Does not initiate the reaction (D) All (A), (B) and (C)

Last Answer : (A) Retards the rate of reaction

A catalyst (a) Alters the velocity of a reaction (b) Increases the velocity of a reaction (c) Decreases the velocity of a reaction (d) Starts a reaction

Description : A catalyst (a) Alters the velocity of a reaction (b) Increases the velocity of a reaction (c) Decreases the velocity of a reaction (d) Starts a reaction

Last Answer : Ans:(a)

A catalyst is a substance which (a) Changes the equilibrium of a reaction so that the concentration of the product increases (b) Increases the rate of reaction and increases the equilibrium concentration of products (c) Hastens the attainment of equilibrium (d) Increases the activation energy

Description : A catalyst is a substance which (a) Changes the equilibrium of a reaction so that the concentration of the product increases (b) Increases the rate of reaction and increases the equilibrium concentration of products (c) Hastens the attainment of equilibrium (d) Increases the activation energy

Last Answer : Ans:(c)

The catalyst in a second order reversible reaction increases the rate of the forward reaction (A) And decreases that of backward reaction (B) And backward reaction equally (C) Only (D) To a greater extent than that of the backward reaction

Description : The catalyst in a second order reversible reaction increases the rate of the forward reaction (A) And decreases that of backward reaction (B) And backward reaction equally (C) Only (D) To a greater extent than that of the backward reaction

Last Answer : (B) And backward reaction equally

When a catalyst increases the rate of forward reaction, the value of rate constant (A) Increases (B) Decreases (C) Remain same (D) Becomes infinite

Description : When a catalyst increases the rate of forward reaction, the value of rate constant (A) Increases (B) Decreases (C) Remain same (D) Becomes infinite

Last Answer : (A) Increases

In a reversible reaction, a catalyst increases the rate of forward reaction (A) Only(B) To a greater extent than that of the backward reaction(C) And decreases that of the backward reaction(D) And the backward reaction equally

Description : In a reversible reaction, a catalyst increases the rate of forward reaction (A) Only (B) To a greater extent than that of the backward reaction (C) And decreases that of the backward reaction (D) And the backward reaction equally

Last Answer : (D) And the backward reaction equally

The reason why a catalyst increases the rate of reaction is that, it (A) Decreases the energy barrier for reaction (B) Increases the activation energy (C) Decreases the molecular collision diameter (D) None of these

Description : The reason why a catalyst increases the rate of reaction is that, it (A) Decreases the energy barrier for reaction (B) Increases the activation energy (C) Decreases the molecular collision diameter (D) None of these

Last Answer : (A) Decreases the energy barrier for reaction

What happens when a catalyst is added to a system at equilibrium? A The reaction follows an alternative pathway of lower activation energy. B The heat of reaction decreases. C The potential energy of the reactants decreases. D The potential energy of the products decreases. E The rate of chemical reaction decreases.

Description : What happens when a catalyst is added to a system at equilibrium? A The reaction follows an alternative pathway of lower activation energy. B The heat of reaction decreases. C The potential ... decreases. D The potential energy of the products decreases. E The rate of chemical reaction decreases.

Last Answer : A The reaction follows an alternative pathway of lower activation energy.

Tachycardia is a condition characterized by (1) heart-rate decreases from the normal (2) heart- rate increases from the normal (3) heart-beat stops (4) heart fails to pump

Description : Tachycardia is a condition characterized by (1) heart-rate decreases from the normal (2) heart- rate increases from the normal (3) heart-beat stops (4) heart fails to pump

Last Answer : (2) heart- rate increases from the normal Explanation: Tachycardia is a heart rate that exceeds the nor-mal resting rate. In general, a resting heart rate over 100 beats per minute is ... a person is at rest. Tachycardia occurs when an abnormality in the heart produces rapid electrical signals.

Tachycardia is a condition characterized by (1) heart-rate decreases from the normal (2) heart- rate increases from the normal (3) heart-beat stops (4) heart fails to pump

Description : Tachycardia is a condition characterized by (1) heart-rate decreases from the normal (2) heart- rate increases from the normal (3) heart-beat stops (4) heart fails to pump

Last Answer : heart- rate increases from the normal

When a catalyst increases the rate of chemical reaction the rate constant :-

Description : When a catalyst increases the rate of chemical reaction the rate constant :-

Last Answer : When a catalyst increases the rate of chemical reaction the rate constant :- A. Increases B. Decreases C. Remains constant D. Becomes infinite

Promoter (A) Initiates a chemical reaction and is a catalyst by itself (B) Alters the position of equilibrium in a reversible reaction (C) Increases the number of active centres by increasing the unevenness of catalyst surface and by creating discontinuities in the crystals(D) All (A), (B) and (C)

Description : Promoter (A) Initiates a chemical reaction and is a catalyst by itself (B) Alters the position of equilibrium in a reversible reaction (C) Increases the number of active centres by increasing the unevenness of catalyst surface and by creating discontinuities in the crystals (D) All (A), (B) and (C)

Last Answer : (C) Increases the number of active centres by increasing the unevenness of catalyst surface and by creating discontinuities in the crystals

A substance which increases the efficiency of a catalyst is termed as: A. Promoter (Answer) B. Activator C. Retarder D. Super catalyst

Description : A substance which increases the efficiency of a catalyst is termed as: A. Promoter (Answer) B. Activator C. Retarder D. Super catalyst

Last Answer : A. Promoter (Answer)

Pick out the correct statement pertaining to catalytic cracking. (A) With increase in the reactor pressure, octane number of gasoline decreases (B) With increase in the reactor temperature, gasoline yield decreases for a given conversion (C) Percentage conversion increases with increase in the catalyst to oil ratio (D) All (A), (B) and (C)

Description : Pick out the correct statement pertaining to catalytic cracking. (A) With increase in the reactor pressure, octane number of gasoline decreases (B) With increase in the reactor temperature, gasoline yield decreases for a given ... with increase in the catalyst to oil ratio (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Bulk diffusion in catalyst pore __________ with increase in pressure. (A) Increases (B) Decreases (C) Remains unchanged (D) Increases exponentially

Description : Bulk diffusion in catalyst pore __________ with increase in pressure. (A) Increases (B) Decreases (C) Remains unchanged (D) Increases exponentially

Last Answer : (B) Decreases

Use of catalyst is a must in the ammonia manufacture, because the reaction is reversible as well as the heat of dissociation of N2 & H2 is high. The presence of promoter along with the catalyst helps in __________ of the catalyst. (A) Stabilisation (B) Increasing the effectiveness (C) Improving the strength & heat resistance (D) All a, b & c

Description : Use of catalyst is a must in the ammonia manufacture, because the reaction is reversible as well as the heat of dissociation of N2 & H2 is high. The presence of promoter along with the catalyst helps in ... B) Increasing the effectiveness (C) Improving the strength & heat resistance (D) All a, b & c

Last Answer : (D) All a, b & c

What is the substance which decreases the rate of a chemical reaction? -Do You Know?

Description : What is the substance which decreases the rate of a chemical reaction? -Do You Know?

Last Answer : answer:

What is the substance which decreases the rate of a chemical reaction?

Description : What is the substance which decreases the rate of a chemical reaction?

Last Answer : Poison

For an ideal gas mixture undergoing a reversible gaseous phase chemical reaction, the equilibrium constant(A) Is independent of pressure(B) Increases with pressure(C) Decreases with pressure(D) Increases /decreases with pressure depending on the stoichiometric co￾efficients of the reaction

Description : For an ideal gas mixture undergoing a reversible gaseous phase chemical reaction, the equilibrium constant (A) Is independent of pressure (B) Increases with pressure (C) Decreases with pressure (D) Increases /decreases with pressure depending on the stoichiometric co￾efficients of the reaction

Last Answer : (B) Increases with pressure

Velocity of a chemical reaction (A) Decreases with increase in temperature (B) Increases with increase of pressure of reactants for all reactions (C) Decreases with increase of reactant concentration (D) None of these

Description : Velocity of a chemical reaction (A) Decreases with increase in temperature (B) Increases with increase of pressure of reactants for all reactions (C) Decreases with increase of reactant concentration (D) None of these

Last Answer : (D) None of these

As the chemical reaction proceeds, the rate of reaction(A) Increases (B) Decreases (C) Remain same (D) May increase or decrease depending on the type of reaction

Description : As the chemical reaction proceeds, the rate of reaction (A) Increases (B) Decreases (C) Remain same (D) May increase or decrease depending on the type of reaction

Last Answer : (B) Decreases

Fractional conversion __________ for an exothermic reversible chemical reaction, when the temperature is maximum. (A) Increases (B) Remains unchanged (C) Decreases (D) Unpredictable from the data

Description : Fractional conversion __________ for an exothermic reversible chemical reaction, when the temperature is maximum. (A) Increases (B) Remains unchanged (C) Decreases (D) Unpredictable from the data

Last Answer : (C) Decreases

What helps speed a chemical reaction?

Description : What helps speed a chemical reaction?

Last Answer : Heat usually speeds up a chemical reaction

Presence of sulphur in gasoline (A) Leads to corrosion (B) Increases lead susceptibility (C) Decreases gum formation (D) Helps during stabilisatio

Description : Presence of sulphur in gasoline (A) Leads to corrosion (B) Increases lead susceptibility (C) Decreases gum formation (D) Helps during stabilisatio

Last Answer : (A) Leads to corrosion

A catalyst increases rate of reaction by

Description : A catalyst increases rate of reaction by

Last Answer : A catalyst increases rate of reaction by A. Decreasing enthalpy B. Decreasing internal ... activation energy D. Increasing activation energy

A Catalyst (A) Increases the equilibrium concentration of the product (B) Changes the equilibrium constant of the reaction (C) Shortens the time to reach the equilibrium (D) None of these

Description : A Catalyst (A) Increases the equilibrium concentration of the product (B) Changes the equilibrium constant of the reaction (C) Shortens the time to reach the equilibrium (D) None of these

Last Answer : (C) Shortens the time to reach the equilibrium

Pick out the wrong statement. (A) Exit age description function (E) and internal age distribution function (I) are related as, E = -(dI/dθ) (B) Chemisorption studies are useful in the determination of catalyst surface area and pore size distribution (C) A higher temperature favours the reaction of higher activation energy (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

Description : Pick out the wrong statement. (A) Exit age description function (E) and internal age distribution function (I) are related as, E = -(dI/dθ) (B) Chemisorption studies are useful in the ... energy (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

Last Answer : (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

What purpose does FeCl3 serve in the electrophilic aromatic substitution reaction between chlorine and benzene? (a) It serves as a radical initiator to produce the chlorine radical needed to propagate the chain reaction. (b) It functions by destabilizing the carbocationic intermediate and thereby increases the rate of H+ loss. (c) It serves as a Lewis base catalyst by reacting with Cl2 to generate chloride ions. (d) It serves as a Lewis acid catalyst by reacting with the Cl2 and thereby activates it toward attack by benzene’s π electrons.

Description : What purpose does FeCl3 serve in the electrophilic aromatic substitution reaction between chlorine and benzene? (a) It serves as a radical initiator to produce the chlorine radical needed to propagate the ... by reacting with the Cl2 and thereby activates it toward attack by benzene's π electrons.

Last Answer : It serves as a Lewis acid catalyst by reacting with the Cl2 and thereby activates it toward attack by benzene’s π electrons.

Hydrogenation of edible vegetable oils (A) Is an exothermic reaction (B) Increases their melting point (C) Is done in presence of nickel catalyst (D) All (A), (B) and (C)

Description : Hydrogenation of edible vegetable oils (A) Is an exothermic reaction (B) Increases their melting point (C) Is done in presence of nickel catalyst (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

It is dangerous to observe solar eclipse with naked eyes because – (1) Infrared radiations from sun burn our retina (2) Ultraviolet radiations from Sun burn our retina (3) All radiations from sun initiate chemical reactions in eyes (4) Cosmic rays reach eyes more during the eclipse

Description : It is dangerous to observe solar eclipse with naked eyes because – (1) Infrared radiations from sun burn our retina (2) Ultraviolet radiations from Sun burn our retina (3) All radiations from sun initiate chemical reactions in eyes (4) Cosmic rays reach eyes more during the eclipse

Last Answer : (2) Ultraviolet radiations from Sun burn our retina Explanation: The solar radiation that reaches the surface of Earth ranges from ultraviolet (UV) radiation at wavelengths longer than 290 nm to radio ... of the Sun during an eclipse is for the development of "eclipse blindness" or retinal burns.

It is dangerous to observe solar eclipse with naked eyes because – (1) Infrared radiations from sun burn our retina (2) Ultraviolet radiations from Sun burn our retina (3) All radiations from sun initiate chemical reactions in eyes (4) Cosmic rays reach eyes more during the eclipse

Description : It is dangerous to observe solar eclipse with naked eyes because – (1) Infrared radiations from sun burn our retina (2) Ultraviolet radiations from Sun burn our retina (3) All radiations from sun initiate chemical reactions in eyes (4) Cosmic rays reach eyes more during the eclipse

Last Answer : (2) Ultraviolet radiations from Sun burn our retina Explanation: The solar radiation that reaches the surface of Earth ranges from ultraviolet (UV) radiation at wavelengths longer than 290 nm to radio ... of the Sun during an eclipse is for the development of "eclipse blindness" or retinal burns.

It is dangerous to observe Solar eclipse with naked eyes because (1) Infrared radiations from sun burn our retina (2) Ultraviolet radiations from Sun burn our retina (3) All radiations from sun initiate chemical reactions in eyes (4) Cosmic rays reach eyes more during the eclipse

Description : It is dangerous to observe Solar eclipse with naked eyes because (1) Infrared radiations from sun burn our retina (2) Ultraviolet radiations from Sun burn our retina (3) All radiations from sun initiate chemical reactions in eyes (4) Cosmic rays reach eyes more during the eclipse

Last Answer : Ultraviolet radiations from Sun burn our retina

With the increase of pressure, the boiling point of any substance - (1) Increases (2) Decreases (3) Remains Same (4) Becomes zero

Description : With the increase of pressure, the boiling point of any substance - (1) Increases (2) Decreases (3) Remains Same (4) Becomes zero

Last Answer : (1) Increases Explanation: The temperature stays the same until all the liquid has vaporized. As the temperature of a liquid rises, the pressure of escaping vapor also rises, and at the boiling point ... vapor is equal to that exerted on the liquid by the surrounding air, causing bubbles to form.

With the increase of pressure, the boiling point of any substance – (1) Increases (2) Decreases (3) Remains Same (4) Becomes zero

Description : With the increase of pressure, the boiling point of any substance – (1) Increases (2) Decreases (3) Remains Same (4) Becomes zero

Last Answer : (1) Increases Explanation: The temperature stays the same until all the liquid has vaporized. As the temperature of a liquid rises, the pressure of escaping vapor also rises, and at the boiling point ... vapor is equal to that exerted on the liquid by the surrounding air, causing bubbles to form.

With increase in porosity, the thermal conductivity of a solid substance (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the solid

Description : With increase in porosity, the thermal conductivity of a solid substance (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the solid

Last Answer : (B) Decreases

With increase in temperature, the internal energy of a substance (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the substance

Description : With increase in temperature, the internal energy of a substance (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the substance

Last Answer : (A) Increases

With increase in temperature, the internal energy of a substance (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the substance

Description : With increase in temperature, the internal energy of a substance (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the substance

Last Answer : (A) Increases

If we increase the pressure on a substance (which is at its triple point), then the triple point (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the substance

Description : If we increase the pressure on a substance (which is at its triple point), then the triple point (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the substance

Last Answer : (C) Remains unchanged

When a solid melts,  a. the temperature of the substance increases.  b. the temperature of the substance decreases.  c. heat leaves the substance.  d. heat enters the substance.

Description : When a solid melts,  a. the temperature of the substance increases.  b. the temperature of the substance decreases.  c. heat leaves the substance.  d. heat enters the substance.

Last Answer : heat enters the substance.

Flywheel is an important part of a steam engine because it – (1) accelerates the speed of the engine (2) helps the engine in keeping the speed uniform (3) decreases the moment of inertia (4) gives strength to the engine

Description : Flywheel is an important part of a steam engine because it – (1) accelerates the speed of the engine (2) helps the engine in keeping the speed uniform (3) decreases the moment of inertia (4) gives strength to the engine

Last Answer : (2) helps the engine in keeping the speed uniform Explanation: A flywheel is a rotating mechanical device that is used to store rotational energy. Flywheels have a. significant moment of ... the Industrial Revolution, James Watt contributed to the development of the flywheel in the steam engine.

Flywheel is an important part of a steam engine because it - (1) gives strength to the engine (2) accelerates the speed of the engine (3) helps the engine in keeping the speed uniform (4) decreases the moment of Inertia

Description : Flywheel is an important part of a steam engine because it - (1) gives strength to the engine (2) accelerates the speed of the engine (3) helps the engine in keeping the speed uniform (4) decreases the moment of Inertia

Last Answer : (3) helps the engine in keeping the speed uniform

Flywheel is an important part of a steam engine because it – (1) accelerates the speed of the engine (2) helps the engine in keeping the speed uniform (3) decreases the moment of inertia (4) gives strength to the engine

Description : Flywheel is an important part of a steam engine because it – (1) accelerates the speed of the engine (2) helps the engine in keeping the speed uniform (3) decreases the moment of inertia (4) gives strength to the engine

Last Answer : (2) helps the engine in keeping the speed uniform Explanation: A flywheel is a rotating mechanical device that is used to store rotational energy. Flywheels have a. significant moment of ... the Industrial Revolution, James Watt contributed to the development of the flywheel in the steam engine.