[A] : Pinus bears resin canals .
[R] : Resin canals are found in cortex and bounded by a glandular epithelial layer that secretes resin.
[A] : Pinus bears resin canals .
[R] : Resin canals are found in cortex and bounded by a glandular epithelial layer that secretes resin.
[R] : Resin canals are found in cortex and bounded by a glandular epithelial layer that secretes resin.
A
If both A and R are true and R is the correct explanation of A
B
If both A and R are true but R is not the correct explanation of A
C
If A is true and R is false
D
If both A and R are false
Text Solution
Verified by Experts
Topper's Solved these Questions
Similar Questions
Explore conceptually related problems
Resin ducts are found in -
Resin got from Pinus is
Silicones are sunthetic polyners conitainging repeated R_2 SiO units . Since the empirical formula is that of a ketone (R_2 CO) , the name Silicone has eeen given to these materils . Siliconse can be makde intio oils , rubbery eleastomers and resins . They find a varely of appoications because of their chemical inctness , water repelling nature m heat resistance and good electical insulationg property . Commerical silicon polumers are usuallly metghly synthesised by the hudroluysis of R_2 SiCl_2 [R = Methyl (Me ) or phenyl ( phi)] . If we mix SiMe_3Cl with SiMe_2Cl_2 , we get silicones of the type .
Read the passage given below and answer the question: Industrially widely applied esterification reactions are commonly catalysed using mineral liquid acids, such as sulphuric acid and p-toluenesulphonic acid. The catalytic activity of homogeneous catalysts is high. They suffer, however, from several drawbacks, such as their corrosive nature, the existence of side reactions, and the fact that the catalyst cannot be easily separated from the reaction mixture. The use of solid acid catalysts offers an alternative and has received a lot of attention in the past years. Solid acid catalysts are not corrosive and, coated onto a support, they can be easily reused. Examples of solid acid catalysts used in esterification reactions include ion-exchange resins, zeolites and superacids like sulphated zirconia and niobium acid. Ion-exchange resins are the most common heterogeneous catalysts used and have proven to be effective in liquid phase esterification and etherification reactions. Because of their selective adsorption of reactants and swelling nature, these resins not only catalyse the esterification reaction but also affect the equilibrium conversion. Shortcomings include insufficient thermal resistance, which limits the reaction temperature to 120^(@)C , preventing widespread use in industry. Zeolites, like Y, X, BEA, ZSM-5 and MCM 41 offer an interesting alternative and have proven to be efficient catalysts for esterification reactions. Zeolites have found wide application in oil refining, petrochemistry and in the production of fine chemicals. Their success is based on the possibility to prepare zeolites with strong Brønsted acidity that can be controlled within a certain range, combined with a good resistance to high reaction temperatures. In this study, the activity of various commercial available solid acid catalysts is assessed with respect to the esterification of acetic acid with butanol. The ion-exchange resins Amberlyst 15 and Smopex-101, the acid zeolites H-ZSM-5, H-MOR, H-BETA and H-USY, and the solid superacids sulphated zirconia and niobium acid are selected. Comparative esterification experiments have been carried out using the homogeneous catalysts sulphuric acid, p toluenesulphuric acid and a heteropolyacid (HPA). The weight-based activity of the heterogeneous catalysts tested is maximum for Smopex 101. The following table gives the activity of different catalysts in the esterification reaction between acetic acid and butanol at 75^(@)C . Here: k_(obs) : observed reaction rate constant ( m^(3) mol^(-1)s^(-1) ) kc catalysed reaction rate constant ( m^(3)mol^(-1) g_(cat)^(-1)s^(-1) ) Please note: k c = k obs/ amount (in g) (source: PETERS, T., BENES, N., HOLMEN, A., & KEURENTJES, J. (2006). Comparison of commercial solid acid catalysts for the esterification of acetic acid with butanol. Applied Catalysis A: General, 297(2), 182-188. doi:10.1016/j.apcata.2005.09.00) Catalysts used in oil refining industry are:
Read the passage given below and answer the question: Industrially widely applied esterification reactions are commonly catalysed using mineral liquid acids, such as sulphuric acid and p-toluenesulphonic acid. The catalytic activity of homogeneous catalysts is high. They suffer, however, from several drawbacks, such as their corrosive nature, the existence of side reactions, and the fact that the catalyst cannot be easily separated from the reaction mixture. The use of solid acid catalysts offers an alternative and has received a lot of attention in the past years. Solid acid catalysts are not corrosive and, coated onto a support, they can be easily reused. Examples of solid acid catalysts used in esterification reactions include ion-exchange resins, zeolites and superacids like sulphated zirconia and niobium acid. Ion-exchange resins are the most common heterogeneous catalysts used and have proven to be effective in liquid phase esterification and etherification reactions. Because of their selective adsorption of reactants and swelling nature, these resins not only catalyse the esterification reaction but also affect the equilibrium conversion. Shortcomings include insufficient thermal resistance, which limits the reaction temperature to 120^(@)C , preventing widespread use in industry. Zeolites, like Y, X, BEA, ZSM-5 and MCM 41 offer an interesting alternative and have proven to be efficient catalysts for esterification reactions. Zeolites have found wide application in oil refining, petrochemistry and in the production of fine chemicals. Their success is based on the possibility to prepare zeolites with strong Brønsted acidity that can be controlled within a certain range, combined with a good resistance to high reaction temperatures. In this study, the activity of various commercial available solid acid catalysts is assessed with respect to the esterification of acetic acid with butanol. The ion-exchange resins Amberlyst 15 and Smopex-101, the acid zeolites H-ZSM-5, H-MOR, H-BETA and H-USY, and the solid superacids sulphated zirconia and niobium acid are selected. Comparative esterification experiments have been carried out using the homogeneous catalysts sulphuric acid, p toluenesulphuric acid and a heteropolyacid (HPA). The weight-based activity of the heterogeneous catalysts tested is maximum for Smopex 101. The following table gives the activity of different catalysts in the esterification reaction between acetic acid and butanol at 75^(@)C . Here: k_(obs) : observed reaction rate constant ( m^(3) mol^(-1)s^(-1) ) kc catalysed reaction rate constant ( m^(3)mol^(-1) g_(cat)^(-1)s^(-1) ) Please note: k c = k obs/ amount (in g) (source: PETERS, T., BENES, N., HOLMEN, A., & KEURENTJES, J. (2006). Comparison of commercial solid acid catalysts for the esterification of acetic acid with butanol. Applied Catalysis A: General, 297(2), 182-188. doi:10.1016/j.apcata.2005.09.00) The catalytic activity of homogeneous catalysts is high. The weight based activity of HPA is less than which of the following heterogenous catalysts?
Read the passage given below and answer the question: Industrially widely applied esterification reactions are commonly catalysed using mineral liquid acids, such as sulphuric acid and p-toluenesulphonic acid. The catalytic activity of homogeneous catalysts is high. They suffer, however, from several drawbacks, such as their corrosive nature, the existence of side reactions, and the fact that the catalyst cannot be easily separated from the reaction mixture. The use of solid acid catalysts offers an alternative and has received a lot of attention in the past years. Solid acid catalysts are not corrosive and, coated onto a support, they can be easily reused. Examples of solid acid catalysts used in esterification reactions include ion-exchange resins, zeolites and superacids like sulphated zirconia and niobium acid. Ion-exchange resins are the most common heterogeneous catalysts used and have proven to be effective in liquid phase esterification and etherification reactions. Because of their selective adsorption of reactants and swelling nature, these resins not only catalyse the esterification reaction but also affect the equilibrium conversion. Shortcomings include insufficient thermal resistance, which limits the reaction temperature to 120^(@)C , preventing widespread use in industry. Zeolites, like Y, X, BEA, ZSM-5 and MCM 41 offer an interesting alternative and have proven to be efficient catalysts for esterification reactions. Zeolites have found wide application in oil refining, petrochemistry and in the production of fine chemicals. Their success is based on the possibility to prepare zeolites with strong Brønsted acidity that can be controlled within a certain range, combined with a good resistance to high reaction temperatures. In this study, the activity of various commercial available solid acid catalysts is assessed with respect to the esterification of acetic acid with butanol. The ion-exchange resins Amberlyst 15 and Smopex-101, the acid zeolites H-ZSM-5, H-MOR, H-BETA and H-USY, and the solid superacids sulphated zirconia and niobium acid are selected. Comparative esterification experiments have been carried out using the homogeneous catalysts sulphuric acid, p toluenesulphuric acid and a heteropolyacid (HPA). The weight-based activity of the heterogeneous catalysts tested is maximum for Smopex 101. The following table gives the activity of different catalysts in the esterification reaction between acetic acid and butanol at 75^(@)C . Here: k_(obs) : observed reaction rate constant ( m^(3) mol^(-1)s^(-1) ) kc catalysed reaction rate constant ( m^(3)mol^(-1) g_("cat")^(-1)s^(-1) ) Please note: k c = k obs/ amount (in g) (source: PETERS, T., BENES, N., HOLMEN, A., & KEURENTJES, J. (2006). Comparison of commercial solid acid catalysts for the esterification of acetic acid with butanol. Applied Catalysis A: General, 297(2), 182-188. doi:10.1016/j.apcata.2005.09.00) Unit for observed rate constant for esterification reaction is m³ mol^-1s^-1 , so the reaction is:
Read the passage given below and answer the question: Industrially widely applied esterification reactions are commonly catalysed using mineral liquid acids, such as sulphuric acid and p-toluenesulphonic acid. The catalytic activity of homogeneous catalysts is high. They suffer, however, from several drawbacks, such as their corrosive nature, the existence of side reactions, and the fact that the catalyst cannot be easily separated from the reaction mixture. The use of solid acid catalysts offers an alternative and has received a lot of attention in the past years. Solid acid catalysts are not corrosive and, coated onto a support, they can be easily reused. Examples of solid acid catalysts used in esterification reactions include ion-exchange resins, zeolites and superacids like sulphated zirconia and niobium acid. Ion-exchange resins are the most common heterogeneous catalysts used and have proven to be effective in liquid phase esterification and etherification reactions. Because of their selective adsorption of reactants and swelling nature, these resins not only catalyse the esterification reaction but also affect the equilibrium conversion. Shortcomings include insufficient thermal resistance, which limits the reaction temperature to 120^(@)C , preventing widespread use in industry. Zeolites, like Y, X, BEA, ZSM-5 and MCM 41 offer an interesting alternative and have proven to be efficient catalysts for esterification reactions. Zeolites have found wide application in oil refining, petrochemistry and in the production of fine chemicals. Their success is based on the possibility to prepare zeolites with strong Brønsted acidity that can be controlled within a certain range, combined with a good resistance to high reaction temperatures. In this study, the activity of various commercial available solid acid catalysts is assessed with respect to the esterification of acetic acid with butanol. The ion-exchange resins Amberlyst 15 and Smopex-101, the acid zeolites H-ZSM-5, H-MOR, H-BETA and H-USY, and the solid superacids sulphated zirconia and niobium acid are selected. Comparative esterification experiments have been carried out using the homogeneous catalysts sulphuric acid, p toluenesulphuric acid and a heteropolyacid (HPA). The weight-based activity of the heterogeneous catalysts tested is maximum for Smopex 101. The following table gives the activity of different catalysts in the esterification reaction between acetic acid and butanol at 75^(@)C . Here: k_(obs) : observed reaction rate constant ( m^(3) mol^(-1)s^(-1) ) kc catalysed reaction rate constant ( m^(3)mol^(-1) g_(cat)^(-1)s^(-1) ) Please note: k c = k obs/ amount (in g) (source: PETERS, T., BENES, N., HOLMEN, A., & KEURENTJES, J. (2006). Comparison of commercial solid acid catalysts for the esterification of acetic acid with butanol. Applied Catalysis A: General, 297(2), 182-188. doi:10.1016/j.apcata.2005.09.00) The weight-based activity of the heterogeneous catalysts tested decreases in the following order:
Read the passage given below and answer the question: Industrially widely applied esterification reactions are commonly catalysed using mineral liquid acids, such as sulphuric acid and p-toluenesulphonic acid. The catalytic activity of homogeneous catalysts is high. They suffer, however, from several drawbacks, such as their corrosive nature, the existence of side reactions, and the fact that the catalyst cannot be easily separated from the reaction mixture. The use of solid acid catalysts offers an alternative and has received a lot of attention in the past years. Solid acid catalysts are not corrosive and, coated onto a support, they can be easily reused. Examples of solid acid catalysts used in esterification reactions include ion-exchange resins, zeolites and superacids like sulphated zirconia and niobium acid. Ion-exchange resins are the most common heterogeneous catalysts used and have proven to be effective in liquid phase esterification and etherification reactions. Because of their selective adsorption of reactants and swelling nature, these resins not only catalyse the esterification reaction but also affect the equilibrium conversion. Shortcomings include insufficient thermal resistance, which limits the reaction temperature to 120^(@)C , preventing widespread use in industry. Zeolites, like Y, X, BEA, ZSM-5 and MCM 41 offer an interesting alternative and have proven to be efficient catalysts for esterification reactions. Zeolites have found wide application in oil refining, petrochemistry and in the production of fine chemicals. Their success is based on the possibility to prepare zeolites with strong Brønsted acidity that can be controlled within a certain range, combined with a good resistance to high reaction temperatures. In this study, the activity of various commercial available solid acid catalysts is assessed with respect to the esterification of acetic acid with butanol. The ion-exchange resins Amberlyst 15 and Smopex-101, the acid zeolites H-ZSM-5, H-MOR, H-BETA and H-USY, and the solid superacids sulphated zirconia and niobium acid are selected. Comparative esterification experiments have been carried out using the homogeneous catalysts sulphuric acid, p toluenesulphuric acid and a heteropolyacid (HPA). The weight-based activity of the heterogeneous catalysts tested is maximum for Smopex 101. The following table gives the activity of different catalysts in the esterification reaction between acetic acid and butanol at 75^(@)C . Here: k_(obs) : observed reaction rate constant ( m^(3) mol^(-1)s^(-1) ) kc catalysed reaction rate constant ( m^(3)mol^(-1) g_(cat)^(-1)s^(-1) ) Please note: k c = k obs/ amount (in g) (source: PETERS, T., BENES, N., HOLMEN, A., & KEURENTJES, J. (2006). Comparison of commercial solid acid catalysts for the esterification of acetic acid with butanol. Applied Catalysis A: General, 297(2), 182-188. doi:10.1016/j.apcata.2005.09.00) Which of the following are heterogeneous catalysts for esterifctaion reaction:
[A]: Rubber is obtained from the latex of Hevea brasiliensis. [R]: Because secretory canals are abun- dantly found in the secondary phloem
TRUEMAN BIOLOGY-(AIPMT(NEET Phase-1)-2016)(Conducted by CBSE on 01-05-2016)(Solved Paper)-MCQs
- [A] : Pinus bears resin canals . [R] : Resin canals are found in cor...
Text Solution
|
- In a testcross involving "F"(1) dihybrid flies, more parental-type off...
Text Solution
|
- Water soluble pigment present in cell vascuole is
Text Solution
|
- Which of the following pairs of hormones are not antagonistic (having ...
Text Solution
|
- Mitochondria and chloroplast are (a) Semi-autonomous organelles (...
Text Solution
|
- Which of the following is not a feature of the plasmids ?
Text Solution
|
- A plant in your garden avoids photorespiratory losses, has improved wa...
Text Solution
|
- Emerson's enhancement effect and red drop have been instrumental in th...
Text Solution
|
- When does the growth rate of a population following the logistic model...
Text Solution
|
- Which one of the following statements is not true ?
Text Solution
|
- Which one of the following statements is wrong
Text Solution
|
- The Avena curvature is used for bioassay of
Text Solution
|
- Which of the following structures is homologus to the wing of a bird?
Text Solution
|
- Blood pressure in the pulmonary artery is
Text Solution
|
- Fertilization in humans is practically feasible only if
Text Solution
|
- In meiosis crossing over is initiated at
Text Solution
|
- Chrysophytes, Euglenoids, Dinoflaegellates and Slime moulds are includ...
Text Solution
|
- Lack of relaxation between successive stimuli in striated muscle contr...
Text Solution
|
- Identify the correct statement on 'inhibin'.
Text Solution
|
- Name the chronic respiratory disorder caused mainly by cigarette smoki...
Text Solution
|
- Which of the following most appropriately describes haemophilia ?
Text Solution
|