Addition of urea to the soil is ------ reaction?
Addition of urea to the soil is ------ reaction?
endothermic | |
no heat energy is involved | |
both a and b | |
exothermic |
پاک اسٹڈی لائبریری اپنی خدمات کو بہتر کرنے کے لئے نئے سوفٹ وئیر انسٹال کررہی ہے ۔ اس لئے آئندہ کچھ دن آپ کو کچھ صفحات تک رسائی میں مشکلات کا سامنا ہوسکتا ہے ۔ جس کے لئے ہم معذرت خواہ ہیں۔
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Addition of urea to the soil is ------ reaction?
endothermic | |
no heat energy is involved | |
both a and b | |
exothermic |
Addition of CH3COOH and CH3COONa gives in water--------?
acidic buffer solution | |
Standard solution | |
buffer solution | |
both B & C |
Addition of 2nd electron to a uni negative ion is always----------?
Endothermic | |
Unpredictable | |
Data is insufficient | |
Exothermic |
Addition of 2% gypsum in cement--------?
all of the above | |
Triggers hydrolysis | |
Prevents rapid hardening | |
Triggers hydration |
Activated complex is formed due to--------?
Temperature | |
Pressure | |
Ineffective collisions | |
Effective collision |
Actinides are the elements with atomic number from:
97 to 104 | |
101 to 115 | |
36 to 43 | |
89 to 103 |
Across short period the melting and boiling point increase upto ---------?
VA group | |
VIA group | |
IIIA group | |
IVA group |
Acidic amino acids have--------?
2 carboxylic groups and 1 amino group | |
1 amino and 1 carboxylic groups | |
2 amino groups and 1 carboxylic group | |
2 amino and 2 carboxylic groups |
Acid present in acid rain may be---------?
H2SO4 | |
HNO3 | |
none | |
both A and B |
Acetophenone is a-----------?
Ketone | |
Ether | |
Aldehyde | |
Ester |
Acetone reacts with HCN to form a cyanohydrin. It is an example of--------?
electrophilic substitution | |
nucleophilic addition | |
electronphilic addition | |
nucleophilic substitution |
Acetic anhydride can be obtained by treating ethyl alcohol with----------?
Both A and B | |
H2SO4 | |
PCI5 | |
P2O5 |
Acetaldehyele cyanohydrin on acid hydrolysis yields----------?
Tartaric acid | |
Lactic acid | |
Propanoic acid | |
Valeric acid |
Acetal on acid hydrolysis generates---------?
Both A & B | |
None of the above | |
Ketone | |
Alcohol |
According to VESPR Model the geometry of molecule having 5 bond pair in outer most shell will be ---------?
Octahedral | |
Triangular | |
Trigonal bipyramidal | |
Square planner |
According to Journal of Biological Chemistry 158, human brain and heart are composed of ----water?
75% | |
89% | |
81% | |
73% |
Absolute alcohol is obtained when rectified spirit is treated with---------?
Ca(OH)2 | |
CaCO3 | |
CaCl2 | |
CaO |
A theoretical link between quantum mechanics and thermodynamics is-----?
Soectroscopic analysis | |
Statistical thermodynamics | |
Electrchemistry | |
Matrix mechanics |
A technique of partition chromatography in which the solvent is in a pool at the bottom of container--------?
Descending chromatography | |
Adsorption chromatography | |
Ascending chromatography | |
Radial chromatography |
A substance which increases the reactivity of enzyme is called---------?
Stimulators | |
Inhibitors | |
Non-activators | |
Promoters |
A substance is analyzed and found to have an emperical formula of CH2 and a molar mass of 56g/mole. What is the molecular formula of the compound?
C4H8 | |
C3H6 | |
C5H10 | |
C2H4 |
A substance having very high vapour pressure at its melting point on heating will show--------?
Melting | |
Sublimation | |
Condensation | |
Decomposition |
A specie with maximum number of unpaired electrons ?
NH-2 | |
F | |
H2O | |
HF |
A solution has pH = 0 its H+ ion concentration is---------?
x 0- | |
1 | |
x 0-4 | |
x 0-7 |
A solution can be both----------?
saturated and super saturated | |
dilute and concentrated | |
saturated and unsaturated | |
dilute and saturated |