List of top Chemistry Questions

For the reaction \( 2A + B \rightleftharpoons C \), \( \Delta H = x \) cal, which one of the following conditions would favour the yield of C on the basis of Le-Chatelier's principle?
The EMF of the cell, \[ \text{Mg}^{2+}(0.01M) \parallel \text{Sn}^{2+}(0.1M) \parallel \text{Sn at 298K} \] is:
Consider the following equation, which represents the reaction in the extraction of chromium from its ore: \[ \text{Fe}_2\text{O}_3 + 4\text{Na}_2\text{Cr}_2\text{O}_7 + 3O_2 \rightarrow 2\text{Fe}_2\text{O}_3 + 4\text{Na}_2\text{CrO}_4 + 3O_2 \] Which of the following statements about the oxidation states of the substances is correct?
A vessel at 1000 K contains CO\(_2\) with a pressure of 0.5 atm. Some of the CO\(_2\) is converted into CO on the addition of graphite. The value of K if the total pressure at equilibrium is 0.8 atm, is:
In the reversible reaction, \[ 2NO_2 \rightleftharpoons \text{N}_2\text{O}_4 \] the rate of disappearance of \( NO_2 \) is equal to:
A chemical reaction was carried out at 300 K and 280 K. The rate constants were found to be \( k_1 \) and \( k_2 \) respectively. Then
The rate constant of a reaction at temperature 200 K is 10 times less than the rate constant at 400 K. What is the activation energy of the reaction?
A crystalline solid:
20 mL of 2.0 M NaOH is added to 50 mL of 0.2 M HCl. The pH of this solution after mixing is:
The radio-isotope used for treatment of thyroid disorders is:
Two glass bulbs A and B are connected by a very small tube having a stop-cock. Bulb A has a volume of 100 cm\(^3\) and contained the gas while bulb B was empty. On opening the stop-cock, the pressure fell down to 40%. The volume of the bulb B must be:
Tetragonal crystal system has the following unit cell dimensions:
"925 fine silver" means an alloy of:
"925 fine silver" means an alloy of:
Self condensation of two moles of ethyl acetate in the presence of sodium ethoxide after acidification yields:
Which one of the following will be most basic?
MnO\(_2\) dissolves in water to give an acid. The color of the acid is:
\( \text{C}_6\text{H}_4\text{Br} \) undergoes Wurtz reaction. We may expect some of the following products:
Which of the following will give Cannizzaro reaction?
The secondary structure of a protein refers to:
Sometimes explosion occurs while distilling ethers. It is due to the presence of:
Glycerine is used as a preservative for fruits and vegetables because:
The reaction is called:
A nucleus \( _{Z}^A X \) emits an \( \alpha \)-particle. The resultant nucleus emits a \( \beta^- \)-particle. The respective atomic and mass numbers of the final nucleus will be:
An alkene having molecular formula \( C_8H_{12} \) on ozonolysis yields glyoxal and 2, 2-dimethyl butane-1, 4-dial. The structure of the alkene is: