JEE Mains · Chemistry · STD 12 - 3. Chemical kinetics
The half-life period of a first order reaction is \(15\,minutes\). The amount of substance left after one hour will be
- A \(\frac{1}{4}\) of the original amount
- B \(\frac{1}{8}\) of the original amount
- C \(\frac{1}{16}\) of the original amount
- D \(\frac{1}{32}\) of the original amount
Answer & Solution
Correct Answer
(C) \(\frac{1}{16}\) of the original amount
Step-by-step Solution
Detailed explanation
Given \(t_{1/2}\,=\,15\,minutes\) Total time \((T)\,=\,1\,hr\,=\,60\,min.\) From \(T\,=\,n\times t_{1/2}\) \(n\,=\,\frac {60}{15}\,=\,4\) Now from the formula \(\frac{N}{{{N_0}}}\, = \,{\left( {\frac{1}{2}} \right)^n}\)…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Chemistry
- \(Ph - CH = CH _2 \xrightarrow[ HBr ]{( PhCOO )_2}\) Product
Consider the above reaction
A. The reaction proceeds through a more stable radical intermediate.
B. The role of peroxide is to generate \(\dot{ H }\) (Hydrogen radical).
C. During this reaction, benzene is formed as a biproduct.
D. 1-Bromo-2-phenylethane is fanned as the minor product.
E. The same reaction in absence of peroxide proceeds via carbocation intermediate.
Identify the correct statements. Choose the correct answer from the options given below:JEE Mains 2026 Easy - The freezing point of diluted milk sample is found to be \(-\,0.2\,^oC,\) while it should have been \(\,0.5\,^oC,\) for pure milk. How much water been added to pure milk to make the diluted sample?JEE Mains 2019 Hard
- Match the LIST-I with LIST-II
LIST-I
(Complex/ Species)LIST-II
(Shape, magnetic moment)A. [Ni(CO)4] I. Tetrahedral, 2.8 BM B. [Ni(CN)4]2- II. Square planar, 0 BM C. [NiCl4]2- III. Tetrahedral, 0 BM D. [MnBr4]2- IV. Tetrahedral, 5.9 BM
Choose the correct answer from the options given below :JEE Mains 2025 Medium - The metal which is extracted by oxidation and subsequent reduction from its ore is :JEE Mains 2023 Medium
- The standard electrode potential \(\left( M ^{3+} / M ^{2+}\right)\) for \(V\), \(Cr , Mn\) and \(Co\) are \(-0.26\,V ,-0.41\,V ,+1.57\,V\) and \(+1.97\,V\), respectively. The metal ions which can liberate \(H _2\) from a dilute acid areJEE Mains 2023 Hard
- \(10\, mL\) of \(1\,mM\) surfactant solution forms a monolayer covering \(0.24\, cm^2\) on a polar substrate. If the polar head is approximated as cube, what is its edge length ?JEE Mains 2019 Hard
More PYQs from JEE Mains
- A system consists of two identical spheres each of mass \(1.5\, {kg}\) and radius \(50\, {cm}\) at the end of light rod. The distance between the centres of the two spheres is \(5\, {m}\). What will be the moment of inertia of the system about an axis perpendicular to the rod passing through its midpoint ? (in \({kgm}^{2}\))JEE Mains 2021 Hard
- Alkaline oxidative fusion of \(\mathrm{MnO}_2\) gives \("A"\) which on electrolytic oxidation in alkaline solution produces \(B. A\) and \(B\) respectively are _______.JEE Mains 2024 Hard
- The total kinetic energy of \(1\) mole of oxygen at \(27^{\circ} \mathrm{C}\) is : [Use universal gas constant \((R)=8.31 \mathrm{~J} / \mathrm{mole} \mathrm{K}\) ]JEE Mains 2024 Hard
- Which of the following compounds will most readily be dehydrated to give alkene under acidic condition?JEE Mains 2018 Hard
- The values of \(\mathrm{m}, \mathrm{n}\), for which the system of equations \( x+y+z=4 \) \( 2 x+5 y+5 z=17 \) \( x+2 y+m z=n\) has infinitely many solutions, satisfy the equation :JEE Mains 2024 Hard
- Identify the correct IUPAC name of hydrocarbon (\(x\)) containing three primary carbon atoms and with molar mass \(72\text{ g mol}^{-1}\).JEE Mains 2026 Medium