Chemistry Question Bank

[NEET 2020] In ¹⁷⁵₇₁Lu, the number of protons, neutrons and electrons respectively are

[NEET 2021] A radio station broadcasts at frequency 1368 kHz. The wavelength of electromagnetic radiation emitted is (c = 3 × 10⁸ m/s)

Pauli's exclusion principle states that

Pairing of electrons in orbitals belonging to the same subshell does not take place until each orbital is singly occupied. This is called

[NEET 2021] From the following pairs, which one is NOT an isoelectronic pair?

Hydrogen evolved at NTP on complete reaction of 27 gm of Al with excess of aq NaOH would be (Chemical reaction: 2Al + 2NaOH + \(\mathrm{H_2O}\) \(\mathrm{NaAlO_2}\) + \(\mathrm{H_2}\)

An ore contains 1.34% of the mineral argentite, \(\mathrm{Ag_2S}\) by weight. How many grams of this ore would have to be processed in order to obtain 1.00 g of pure solid silver, Ag?

The number of electron in the telluride ion. \(\mathrm{Te_2}\) is

What is the total number of atoms present in 25.0 mg of camphor \(\mathrm{C_10H_16O}\)

Chlorophyll contains 2.68% of magnesium by mass. Calculate the number of magnesium atoms in 3.00 gms of chlorophyll.

At room temperature and pressure two flask of equal volumes are filled with \(\mathrm{H_2}\) and \(\mathrm{SO_2}\) respectively. Particles which are equal in number in two flasks are

Simplest formulae of a compound containing 20% of element X (atomic weight 10) and 80% of element Y (atomic weight 20) is

Which of the following samples contains 2.0 1023 atoms?

A copper sulphate solution contains 1.595% of \(\mathrm{CuSO_4}\) by weight. Its density is 1.2 g / ml, Its molarity will be

6.023 ×1023 molecules of Ca (OH)₂ react with 3.01×1022 molecules of HCl, number of moles of \(\mathrm{CaCl_2}\) obtained are

The \(\mathrm{O_18O_16}\) ratio in some meteorites is greater than that used to calculate the average atomic mass of oxygen on earth. The average mass of an atom of oxygen in these meteorites is ………. that of a terrest…

An element, X, have three isotopes X 20, X 21 and X 22. The percentage abundance of X 20is 90% and its average atomic mass of the element is 20.11. The percentage abundance of X 21 should be

An organic compound on analysis was found to contain 0.014% of nitrogen. If its molecule contains two N atoms, then the molecular mass of the compound

A compound contains 28% nitrogen and 72% metal by mass 3 atoms of the metal combine with 2 atoms of nitrogen. The atomic mass of metal is

A partially dried clay mineral contains 8% water. The original sample contained 12% water and 45% silica. % of Silica in the partially dried sample is nearly

Cortisone is a molecular substance containing 21 atoms of carbon per molecule. The weight percentage of carbon in cortisone is 69.98%. What is the molecular weight of cortisone?

The charge on 1 gram ion of \(\mathrm{Al_3}\) is (e represents magnitude of charge on 1 electron)

Which one of the following statements is not correct?

Which of the following weighs the least

The no. of moles of carbon dioxide which contain 8g of oxygen is