19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
An organic compound has an empirical formula CH O . It’s vapour density is 45. The molecular formula of the compound is
The empirical formula of a compound is CH₂. One mole of this compound has a mass of 42 g. Its molecular formula is
The simplest formula of a compound containing 50% of an element X (atomic weight 10) and 50% of element Y (atomic weight 20) is :
A compound was found in contain 21.67% Mg, 21.4% C and 57.0% O by mass of oxygen. What is the simplest formula of this compound ?
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
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 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 :