19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
What is the empirical formula of a compound composed of O and Mn in equal weight ratio?
An oxide of metal (M) has 40% by mass of oxygen. Metal M has atomic mass of 24. The empirical formula of the oxide is
A gas has molecular formula (CH)n. If vapour density of the gas is 39, what should be the formula of the compound?
An organic compound containing C and H has 92.3% of carbon, its empirical formula is
A Compound contains 69.5% oxygen and 30.5% nitrogen and its molecular weight is 92. The molecular formula of compound is
If two compounds have the same empirical formula but different molecular formula, they must have
What is the percentage of carbon, in ethanol?
Mass % of an element A 100 Molar mass of compound x Here, A refers to
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 ratio of masses of oxygen and nitrogen in a particular gaseous mixture is 1: 4. The ratio of number of their molecule is :
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 ?
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 ?
What’s the number of particles in 10 moles of hydrochloric acid? a) 6.022 × 1024 particles b) 6.022 × 1023 particles c) 6.22 × 1023 particles d) 3.22 × 1022 particles
If one mole of ammonia contains “y” number of particles, then how many particles do 1 mole of glucose contain?
According to S.I. system, ______ was used to measure the amount of substance.
Which of the following gases will have the least volume if 10 g of each gas is taken at same temperature and pressure?