JEE Mains · Chemistry · STD 11 - 1. Some basic concept of chemistry
The density of ' \(x\) ' \(\mathrm{M}\) solution (' \(\mathrm{x}\) ' molar) of \(\mathrm{NaOH}\) is \(1.12 \mathrm{~g} \mathrm{~mL}^{-1}\). while in molality, the concentration of the solution is \(3 \mathrm{~m}\) ( \(3 \mathrm{molal})\). Then \(\mathrm{x}\) is _______. (Given : Molar mass of \(\mathrm{NaOH}\) is \(40 \mathrm{~g} / \mathrm{mol}\) )
- A \(3.5\)
- B \(3.0\)
- C \(3.8\)
- D \(2.8\)
Answer & Solution
Correct Answer
(B) \(3.0\)
Step-by-step Solution
Detailed explanation
\(\text { Molality }=\frac{1000 \times \mathrm{M}}{1000 \times \mathrm{d}-\mathrm{M} \times(\mathrm{Mw})_{\text {solute }}}\) \(3=\frac{1000 \times \mathrm{x}}{1000 \times 1.12-(\mathrm{x} \times 40)}\) \(\mathrm{x}=3\)
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
- The spin-only magnetic moment value of \(M ^{3+}\) ion (in gaseous state) from the pairs \(Cr ^{3+} / Cr ^{2+}\), \(Mn ^{3+} / Mn ^{2}, Fe ^{3+} / Fe ^{2+}\) and \(Co ^{3+} / Co ^{2+}\) that has negative standard electrode potential, is \(B.M...........\) [Nearest integer]JEE Mains 2022 Medium
- Match List-I with List-II -
List-I (Separation of) List-II (Separation Technique) (A) Aniline from aniline-water mixture (I) Simple distillation (B) Glycerol from spent-lye in soap industry (II) Fractional distillation (C) Different fractions of crude oil in petroleum industry (III) Distillation at reduced pressure (D) Chloroform - Aniline mixture (IV) Steam distillation
Choose the correct answer from the options given below:JEE Mains 2025 Medium - Which one among the following chemical tests is used to distinguish monosaccharide from disaccharide?JEE Mains 2021 Easy
- The number of species below that have two lone pairs of electrons in their central atom is ..... . (Round off to the Nearest integer) \(SF _{4}, BF _{4}^{-}, CIF _{3}, AsF _{3}, PCl _{5}, BrF _{5}, XeF _{4}, SF _{6}\)JEE Mains 2021 Medium
- An exothermic reaction \(X \rightarrow Y\) has an activation energy \(30\, kJ \,mol ^{-1}\). If energy change \(\Delta E\) during the reaction is \(-20\, kJ ,\) then the activation energy for the reverse reaction in \(kJ\) is \(...\).(Integer answer)JEE Mains 2021 Easy
- Consider the following equilibrium, \(\mathrm{CO}(\mathrm{g})+2 \mathrm{H}_2(\mathrm{g}) \rightleftharpoons \mathrm{CH}_3 \mathrm{OH}(\mathrm{g})\) 0.1 mol of CO along with a catalyst is present in a \(2 \mathrm{dm}^3\) flask maintained at 500 K. Hydrogen is introduced into the flask until the pressure is 5 bar and 0.04 mol of \(\mathrm{CH}_3 \mathrm{OH}\) is formed. The \(\mathrm{K}_{\mathrm{p}}^0\) is ______ \(\times 10^{-3}\) (nearest integer).
Given : \(\mathrm{R}=0.08 \mathrm{dm}^3\) bar \(\mathrm{K}^{-1} \mathrm{~mol}^{-1}\)
Assume only methanol is formed as the product and the system follows ideal gas behaviour.JEE Mains 2025 Medium
More PYQs from JEE Mains
- Given,
(A) \(n =5, m_1=-1\)
(B) \(n =3,1=2, m_1=-1, m_{ s }=+\frac{1}{2}\)
The maximum number of electron(s) in an atom that can have the quantum numbers as given in (A) and (B) respectively are :JEE Mains 2026 Medium - Let \(a-2 b+c=1\) If \(f(x)=\left|\begin{array}{lll}{x+a} & {x+2} & {x+1} \\ {x+b} & {x+3} & {x+2} \\ {x+c} & {x+4} & {x+3}\end{array}\right|,\) thenJEE Mains 2020 Hard
- There is a small source of light at some depth below the surface of water (refractive index \(=\frac{4}{3}\) ) in a tank of large cross sectional surface area. Neglecting any reflection from the bottom and absorption by water, percentage of light that emerges out of surface is (nearly)...........\(\%\) [Use the fact that surface area of a spherical cap of height \(\mathrm{h}\) and radius of curvature \(\mathrm{r} \text { is } 2 \pi \mathrm{rh}]\)JEE Mains 2020 Hard
- \(40^{\circ}\) of \(HI\) undergoes decomposition to \(H _{2}\) and \(I _{2}\) at \(300\, K . \Delta G ^{\ominus}\) for this decompostion reaction at one atmosphere pressure is \(...\,J\, mol ^{-1} \cdot\) [nearest integer] (Use \(R =8.31\, J\, K ^{-1}\, mol ^{-1} ; \log 2=0.3010\). In \(10=\) \(2.3, \log 3=0.477\) )JEE Mains 2022 Medium
- Space between two concentric conducting spheres of radii \(a\) and \(b (b > a)\) is filled with \(a\) medium of resistivity \(\rho \). The resistance between the two spheres will beJEE Mains 2019 Hard
- The number of solutions of the equation \(1 + {\sin ^4}\,x = {\cos ^2}\,3x,x\,\in \,\left[ { - \frac{{5\pi }}{2},\frac{{5\pi }}{2}} \right]\) isJEE Mains 2019 Hard