19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
If 1021 molecules are removed from 200mg of CO₂, then the number of moles of CO₂ left are
The weight of 1 × 1022 molecules of CuSO₄. 5H₂O is
Which has maximum number of atoms?
The number of water molecules present in a drop of water (volume = 0.0018 ml) at room temperature is (density of H₂O = 1 g/mL)
The largest number of molecules is in
Rearrange the following I to IV in order of increasing masses and choose the correct answer [At. wt. of N = 14 u, O = 16 u, Cu = 63 u] I 1 molecule of oxygen II 1 atom of nitrogen III 1 × 10–10mol molecule of oxygen…
Which among the following is the heaviest?
If NA is Avogadro’s number then number of valence electrons in 4.2 g of nitride ions (N₃–) is
Which of the following weighs the least ?
Which has the highest mass ?
If 1 12 moles of oxygen combine with Al to form Al₂O₃, the weight of Al used in the reaction is (Al = 27)
Which of the following contains atoms equal to those in 12 g Mg ? (At. wt. Mg = 24)
Which of the following represents 180 g of water correctly? (I) 5 moles of water. (II) 10 moles of water. (III) 6.023 × 1023 molecules of water. (IV) 6.023 × 1024 molecules of water. Choose the correct option.
The mass of 112 cm3 of CH₄ gas at STP is
The number of molecules in 89.6 litre of a gas at NTP are :
Number of molecules in 1 litre of oxygen at STP is : (a) 6.02×10 (b) 6.02×10 22.4
M g of a substance when vaporised occupy a volume of 5.6 litre at NTP. The molecular mass of the substance will be :
The weight of one molecule of the compound C₆₀H₁₂₂ is
The number of molecules in 4.25 g of ammonia is about
How many H₂O molecules are in a 0.10g sample of CuSO₄.5H₂O (M = 249.7) ?
A gaseous mixture contains oxygen and nitrogen in the ratio of 1 : 4 by weight. Therefore, the ratio of their number of molecules is
How many moles of magnesium phosphate, Mg₃ (PO₄)₂ will contain 0.25 mole of oxygen atoms ?
Which of the following gases will have the least volume if 10 g of each gas is taken at same temperature and pressure?
Given that the abundances of isotopes 54Fe, 56Fe and 57Fe are 5%, 90% and 5%, respectively, the atomic mass of Fe is
Calculate the molecular mass of sucrose (C₁₂H₂₂O₁₁) molecule?