Home
Class 12
CHEMISTRY
To know the numerical value of a rate ex...

To know the numerical value of a rate expression, we muyst know the concentration or the pressure of a substance at two different times during the course of a reaction. This information can be obtained experimentally, if we have a method of

A

measuring time

B

concentration or pressure

C

keeping the conditions, especially the temperature constant

D

all of these

Text Solution

Verified by Experts

The correct Answer is:
D
The rate of a chemical reaction can be expressed as a given change in a given interval of time. The rate usually is expressed in termp of the change in the concentration or the pressure of one component. It may be expressed as a decrease in the concentration ( or pressure ) of a reactant or an increase in the concentration (or pressure ) of a product.
Promotional Banner

Topper's Solved these Questions

  • CHEMICAL KINETICS

    R SHARMA|Exercise Follow-up 2|10 Videos

  • CHEMICAL KINETICS

    R SHARMA|Exercise Follow-up 3|10 Videos

  • CHEMICAL KINETICS

    R SHARMA|Exercise Archives|39 Videos

  • BIOMOLECULES

    R SHARMA|Exercise Archives|47 Videos

  • CHEMISTRY IN EVERYDAY LIFE

    R SHARMA|Exercise Archives|11 Videos

Similar Questions

Explore conceptually related problems

2A rarrC+D In this reaction, if we double the concentration of A, reaction rate become , two time .. What is the order of this reaction ?

Relating the different ways of expressing reaction rates: Ethanol (CH_(3)CH_(2)OH) , the avtive ingredient in alcoholic beverges and an octane booster in gasoline, is yielded by fermentation of glucose. The balance chemical equation is C_(6)H_(12)O_(6)(aq.)overset("zymase")rarr 2CH_(3)CH_(2)OH(aq.)+2CO_(2)(g) How is the rate of formation of ethanol related to the rate of consumption of glucose ? Strategy : The rate of disappearance of a reactant X is -Delta[X]//Delta t while the rate of appearance of a product Y is Delta[Y]//Delta t . We can express the rate of the reaction in terms of either rate expressoin. To find the relative rates, look at the coefficients in the balanced chemical equation. These rate expressions can be equated , if we first divide each by the coefficient of the corresponding substance in the chemical equation.

The rate of a reaction, which may also be called its velocity or speed, can be defined with relation to the concentration of any of the reacting substances, or to that of any product of the reaction. If the species chosen is a reactant which has a concentration c at time t the rate is - dc/dt, while the rate with reference to a product having a concentration x at time t is dx/dt. Any concentration units may be used for expressing the rate, thus, if moles per liter are employed for concentration and seconds for the time, the units for the rate are moles "liter"^(-1) sec^(-1) . For gas reactions pressure units are sometimes used in place of concentrations, so that legitimate units for the rate would be (mm. Hg) sec^(-1) and atm. sec^(-1) The order of a reaction concerns the dependence of the rate upon the concentrations of reacting substances, thus, if the rate is found experimentally to be proportional to the alpha^(th) power of the concentration of one of the reactants A, to the beta^(th) power of the concentration of a second reactant B, and so forth, via., rate kC_(A)^(alpha) C_(B)^(beta)" " (1) the over-all order of the reaction is simply n = alpha +beta + ---------(2) Such a reaction is said to be of the alpha^(th) order with respect to the substance A, the beta^(th) order with respect to B and so on... (Laidler, K. J., & Glasstone, S. (1948). Rate, order and molecularity in chemical kinetics. Journal of Chemical Education, 25(7), 383.) In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage. Assertion: Rate of reaction is a measure of change in concentration of reactant with respect to time. Reason: Rate of reaction is a measure of change in concentration of product with respect to time.

The rate of a reaction, which may also be called its velocity or speed, can be defined with relation to the concentration of any of the reacting substances, or to that of any product of the reaction. If the species chosen is a reactant which has a concentration c at time t the rate is - dc/dt, while the rate with reference to a product having a concentration x at time t is dx/dt. Any concentration units may be used for expressing the rate, thus, if moles per liter are employed for concentration and seconds for the time, the units for the rate are moles "liter"^(-1) sec^(-1) . For gas reactions pressure units are sometimes used in place of concentrations, so that legitimate units for the rate would be (mm. Hg) sec^(-1) and atm. sec^(-1) The order of a reaction concerns the dependence of the rate upon the concentrations of reacting substances, thus, if the rate is found experimentally to be proportional to the alpha^(th) power of the concentration of one of the reactants A, to the beta^(th) power of the concentration of a second reactant B, and so forth, via., rate kC_(A)^(alpha) C_(B)^(beta)" " (1) the over-all order of the reaction is simply n = alpha +beta + ---------(2) Such a reaction is said to be of the alpha^(th) order with respect to the substance A, the beta^(th) order with respect to B and so on... (Laidler, K. J., & Glasstone, S. (1948). Rate, order and molecularity in chemical kinetics. Journal of Chemical Education, 25(7), 383.) In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage. Assertion: Reactions can occur at different speeds. Reason: Rate of reaction is also called speed of reaction.

The rate of a reaction, which may also be called its velocity or speed, can be defined with relation to the concentration of any of the reacting substances, or to that of any product of the reaction. If the species chosen is a reactant which has a concentration c at time t the rate is - dc/dt, while the rate with reference to a product having a concentration x at time t is dx/dt. Any concentration units may be used for expressing the rate, thus, if moles per liter are employed for concentration and seconds for the time, the units for the rate are moles "liter"^(-1) sec^(-1) . For gas reactions pressure units are sometimes used in place of concentrations, so that legitimate units for the rate would be (mm. Hg) sec^(-1) and atm. sec^(-1) The order of a reaction concerns the dependence of the rate upon the concentrations of reacting substances, thus, if the rate is found experimentally to be proportional to the alpha^(th) power of the concentration of one of the reactants A, to the beta^(th) power of the concentration of a second reactant B, and so forth, via., rate kC_(A)^(alpha) C_(B)^(beta)" " (1) the over-all order of the reaction is simply n = alpha +beta + ---------(2) Such a reaction is said to be of the alpha^(th) order with respect to the substance A, the beta^(th) order with respect to B and so on... (Laidler, K. J., & Glasstone, S. (1948). Rate, order and molecularity in chemical kinetics. Journal of Chemical Education, 25(7), 383.) In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage. Assertion: For a reaction: P +2Q to Products, Rate =k [P]^(1//2)[Q]^(1) so the order of reaction is 1.5 Reason: Order of reaction is the sum of stoichiometric coefficients of the reactants.

The rate of a reaction, which may also be called its velocity or speed, can be defined with relation to the concentration of any of the reacting substances, or to that of any product of the reaction. If the species chosen is a reactant which has a concentration c at time t the rate is - dc/dt, while the rate with reference to a product having a concentration x at time t is dx/dt. Any concentration units may be used for expressing the rate, thus, if moles per liter are employed for concentration and seconds for the time, the units for the rate are moles "liter"^(-1) sec^(-1) . For gas reactions pressure units are sometimes used in place of concentrations, so that legitimate units for the rate would be (mm. Hg) sec^(-1) and atm. sec^(-1) The order of a reaction concerns the dependence of the rate upon the concentrations of reacting substances, thus, if the rate is found experimentally to be proportional to the alpha^(th) power of the concentration of one of the reactants A, to the beta^(th) power of the concentration of a second reactant B, and so forth, via., rate kC_(A)^(alpha) C_(B)^(beta)" " (1) the over-all order of the reaction is simply n = alpha +beta + ---------(2) Such a reaction is said to be of the alpha^(th) order with respect to the substance A, the beta^(th) order with respect to B and so on... (Laidler, K. J., & Glasstone, S. (1948). Rate, order and molecularity in chemical kinetics. Journal of Chemical Education, 25(7), 383.) In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage. Assertion: The unit of k is independent of order of reaction. Reason: The unit of k is moles L^(-1)s^(-1) .