List of top Chemistry Questions

The uncertainty in the determination of the position of a small ball of mass 10 g is \(10^{-33}\) m. With what \% of accuracy can its speed be measured, if it has a speed of 52.5 m s\(^{-1}\)?
At 25°C and 1 atm pressure, the enthalpy of combustion of benzene (l) and acetylene (g) are \(3268 \, \text{kJ mol}^{-1}\) and \(1300 \, \text{kJ mol}^{-1}\), respectively. The change in enthalpy for the reaction 
the enthalpyis
The Enthalpy of combustion of C$_6$H$_6$COOH(s) at 25$^\circ$C and 1.0 atm pressure is -2546 kJ/mol. What is the Internal energy change for this reaction?
What is the quantity of current required to liberate 16g of O\(_2\) (g) during electrolysis of water? (Given 1F = 96500C)
Oxidation number of H in NaH, CaH$_2$, and LiH, respectively is:
Match List I with List II.
List I
(Molecule)		List II
(Number and types of bond/s between two carbon atoms)
A.ethaneI.one σ-bond and two π-bonds
B.etheneII.two π-bonds
C.carbon molecule, C2III.one σ-bonds
D.ethyneIV.one σ-bond and one π-bond
Choose the correct answer from the options given below:
The rate of a reaction quadruples when temperature changes from 27°c to 57°c. Calculate the energy of activation
Given R=8.314 J K-1 mol-1, log 4=0.6021
The plot of osmotic pressure II) vs concentration (mol L–1 ) for a solution gives a straight line with slope 25.73 L bar mol–1 . The temperature at which the osmotic pressure measurement is done is
(Use R = 0.083 L bar mol–1 K–1 )
Law of octaves was proposed by
Element with atomic number 17 belongs to
Oxygen gains ____________________ electrons during the chemical changes.
Number of bond pairs and lone pairs in the valence shell of nitrogen in NH\(_3\)
Ionization energy along a period from left to right generally
Which one of the following atoms is smaller in size?
If the hydrogen atom of -COOH gets replaced by 'R' (alkyl group) _______________ are obtained.
The hydrocarbons containing only single bonds between carbon atoms are called
In smelting the ore it is
The metal that occurs in the free form (native) is
Galena is an ore of
Which of the following is an unsaturated compound?
The reaction of an acid with a base to give a salt and water is known as
The process of conversion of starches and sugars to C2H5OH is called
Maximum no. of electrons in a subshell is equal to
The colour of methyl orange indicator in basic solution is
Which one of the following is used for disinfecting drinking water?