19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
A solution is made by dissolving 49 g of H2SO4 in 250 mL of water. The molarity of the solution prepared is
A solution is prepared by adding 2g of a substance A to 18 g of water. Calculate the mass percent of the solute.
According to the law of conservation of mass …A… has the same number of atoms of each element on both sides of the equation. Here, A refers to
Determine the empirical formula of Kelvar, used in making bullet proof vests, is 70.6% C, 4.2% H, 11.8% N and 13.4% O
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
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
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 ?
The number of moles of SO2Cl2 in 13.5 g is :
Choose the wrong statement:
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) ?