List of top Chemistry Questions

Given below are two statements:
Statement I: Benzendiazonium salt is prepared by the reaction of aniline with nitrous acid at 273-278 K. It decomposes easily in the dry state.
Statement II: Insertion of iodine into the benzene ring is difficult and hence iodobenzene is prepared through the reaction of benzendiazonium salt with KI.
In the light of the above statements, choose the most appropriate answer from the options given below:

Sugar ‘X’:
A. is found in honey.
B. is a keto sugar.
C. exists in $\alpha$ and $\beta$ anomeric forms.
D. is laevorotatory.
‘X’ is:

Identify the suitable reagent for the following conversion: $Ph-C(=O)-OCH_3$ $\longrightarrow$ $Ph-CHO$

The major product of the following reaction is:
$Ph-C(=O)-CH_2CH_2-CN$
(i) $CH_{3}MgBr (excess) (ii) H_{+}H_{2}O$

How many products (including stereoisomers) are expected from monochlorination of the following compound?
$CH_3-CH-CH_2-CH_3$

Which one of the following compounds can exist as cis-trans isomers?

Electrolysis of 600 mL aqueous solution of NaCl for 5 min changes the pH of the solution to 12. The current in Amperes used for the given electrolysis is ….. (Nearest integer).

How many moles are present in $44\, \text{g}$ of $CO_2$?
(Molar mass of $CO_2 = 44\, \text{g/mol}$)

Total number of possible isomers (both structural as well as stereoisomers) of cyclic ethers of molecular formula $C_{4}H_{8}O$ is:

What is Insulin chemically?

How much water must be added to 500 mL of 2 M $ \mathrm{H_2SO_4} $ solution to make it 0.5 M?

Give the reason for low concentration of oxygen in the blood and tissues of people living at high altitude.

The rate constant for a first-order reaction is $ 0.0693 \, \text{min}^{-1} $. What is the half-life of the reaction?

What volume of oxygen gas at STP is required to completely burn 12 g of methane ($ \text{CH}_4 $)? (Molar mass of $ \text{CH}_4 = 16 \, \text{g/mol} $, 1 mole of gas at STP occupies $ 22.4 \, \text{L} $).

What is the molar mass of NaCl?

Which of the following compounds will give a positive Iodoform test?

Calculate the number of moles present in 9.10 × 10¹⁶ kg of water.

Which of the following compounds is used to cover the surface of a metallic object to prevent corrosion?

What is the color of the complex $[Ni(en)_3]^{2+}$ in water?

Which of the following gases has the lowest solubility in water at 298 K?

Hardness of water is estimated by titration with

Which of the following molecules has 3 bond pairs and 2 lone pairs of electrons?

The product obtained on the reaction of propanone with $ CH_3MgBr $ followed by hydrolysis is

The bond angle of Cr-O-Cr bond in dichromate ion is

Which of the following transition elements has both bcc and ccp structures at normal temperature?