List of top Chemistry Questions on Some basic concepts of chemistry

What will be the significant figure of the summation of 0.153, 153.2, and 1532?
The technique used for purification of steam volatile water immiscible substance is:
Following Kjeldahl's method, 1g of organic compound released ammonia that neutralized 10 mL of 2M H\(_2\)SO\(_4\). The percentage of nitrogen in the compound is _________.%.
The fragrance of flowers is due to the presence of some steam volatile organic compounds called essential oils. These are generally insoluble in water at room temperature but are miscible with water vapour in vapour phase. A suitable method for the extraction of these oils from the flowers is -
Match List I with List II
\(\begin{array}{|c|c|c|} \hline \text{LIST I (Technique)} & & \text{LIST II (Application)} \\ \hline \text{A. Distillation} & & \text{I. Separation of glycerol from spent-lye} \\ \text{B. Fractional distillation} & & \text{II. Aniline - Water mixture} \\ \text{C. Steam distillation} & & \text{III. Separation of crude oil fractions} \\ \text{D. Distillation under reduced pressure} & & \text{IV. Chloroform-Aniline} \\ \hline \end{array}\)
Choose the correct answer from the options given below:
A compound X contains 32% of A, 20% of B and remaining percentage of C. Then, the empirical formula of X is:
(Given atomic masses of A=64; B=40; C=32 u)

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R) 
Assertion (A) : An aqueous solution of \(KOH\) when used for volumetric analysis, its concentration should be checked before the use 
Reason (R) : On aging,\(KOH\) solution absorbs atmospheric \(CO _2\)
In the light of the above statements, choose the correct answer from the options given below :

When a hydrocarbon A undergoes complete combustion it requires 11 equivalents of oxygen and produces 4 equivalents of water. What is the molecular formula of $A$?

A sample of a metal oxide has formula $M _{0.83} O _{1.00}$ The metal $M$ can exist in two oxidation states $+2$ and $+3$ In the sample of $M _{0.83} O _{1.00}$, the percentage of metal ions existing in $+2$ oxidation state is___$ \%$ (nearest integer)

How many moles of Ba3(PO4)2 will be formed by the reaction of 5 moles of BaCl2 and 3 moles of Na3(PO4).

0.5 gm of an organic compound with 60%. Carbon produce ______ gm of \(CO_{2}\) upon complete combustion
An organic compound on combustion gives 0.22 g of CO2 and 0.126 g of H2O. If the percentage of C in given organic compound is 40%, the percentage of H will be?
25% of 250g sugar solution & 40% of 500g sugar solution are mixed then find out the mass percentage in the solution.
Read the following two statements:
Statement I: Potassium dichromate is used in volumetric analysis.
Statement II: \(K_2Cr_2O_7\) is more soluble in water than \(Na_2Cr_2O_7\)
How many moles of \(Ba_3(PO_4)_2\) will be formed by the reaction of \(5\) moles of \(BaCl_2\) and \(3\) moles of \(Na_3(PO_4)\).
At 300 K, a sample of 3.0 g of gas A occupies the same volume as 0.2 g of hydrogen at 200 K at the same pressure. The molar mass of gas A is _____ g mol–1. (nearest integer)
Assume that the behaviour of gases as ideal.
(Given: The molar mass of hydrogen (H2) gas is 2.0 g mol–1).
When 800 mL of 0.5 M nitric acid is heated in a beaker, its volume is reduced to half and 11.5 g of nitric acid is evaporated. The molarity of the remaining nitric acid solution is \(x × 10^{–2} M\). (Nearest integer)
(Molar mass of nitric acid is 63 g mol–1)
Metal deficiency defect is shown by \(Fe_{0.93}O\). In the crystal, some \(Fe^{2+}\) cations are missing and loss of positive charge is compensated by the presence of \(Fe^{3+}\) ions. The percentage of \(Fe^{2+}\) ions in the \(Fe_{0.93}O\) crystals is ______ . (Nearest integer)
100 mL of Na\(_3\)PO\(_4\) solution contains 3.45 g of sodium. The molarity of the solution is __________ \(\times\)10\(^{-2}\) mol L\(^{-1}\). (Nearest integer)
[Atomic Masses - Na: 23.0 u, O: 16.0 u, P: 31.0 u]
100 g of propane is completely reacted with 1000 g of oxygen. The mole fraction of carbon dioxide in the resulting mixture is \(x \times 10^{-2}\). The value of x is _________. (Nearest integer)
[Atomic weight : H=1.008; C=12.00; O=16.00]
The molarity of the solution prepared by dissolving \(6.3\text{ g}\) of oxalic acid (\(\text{H}_2\text{C}_2\text{O}_4 \cdot 2\text{H}_2\text{O}\)) in \(250\text{ mL}\) of water in mol L\(^{-1}\) is \(x \times 10^{-2}\). The value of \(x\) is \(\dots\dots\dots\). (Nearest integer)
[Atomic mass : H : 1.0, C : 12.0, O : 16.0]
The major components in “Gun Metal” are :
A $10\, mg$ effervescent tablet contianing sodium bicarbonate and oxalic acid releases $0.25\, ml$ of ${CO_2}$ at $T$ = $298.15\, K$ and $p = 1$ bar. If molar volume of ${CO_2}$ is $25.0\, L$ under such condition, what is the percentage of sodium bicarbonate in each tablet ? [Molar mass of ${NaHCO_3 = 84 \; g \; mol^{-1}}$]
$50\, mL$ of $0.5\, M$ oxalic acid is needed to neutralize $25\, mL$ of sodium hydroxide solution. The amount of $NaOH$ in $50\, mL$ of the given sodium hydroxide solution is :
$5$ moles of $AB_2$ weigh $125 \times 10^{-3}\; kg$ and $10$ moles of $A_2B_2$ weigh $300 \times 10^{-3} \; kg$. The molar mass of $A(M_A)$ and molar mass of $B(M_B) $ in $kg\, mol^{-1}$ are :