List of top Chemistry Questions on Stoichiometry and Stoichiometric Calculations asked in WBJEE

The compound(s) showing optical activity is/are
How many oxygen atoms are present in 0.36 g of a drop of water at STP?
An LPG (Liquified Petroleum Gas) cylinder weighs 15.0 kg when empty. When full, it weighs 30.0 kg and shows a pressure of 3.0 atm. In the course of usage at 27°C, the mass of the full cylinder is reduced to 24.2 kg. The volume of the used gas in cubic metre at the normal usage condition (1 atm and 27°C) is (assume LPG to be normal butane and it behaves ideally):
Arrange the following in order of increasing mass :
(i) 1 mole of N2, (ii) 0.5 mole of O3, (iii) \(3.011×10^{23}\) molecules of O2, (iv) 0.5 gram atom of O2
A metal ($M$) forms two oxides. The ratio $M:O$ (by weight) in the two oxides are $25:4$ and $25:6$. The minimum value of atomic mass of $M$ is
$C_6H_6(\text{liquid}) + \frac{15}{2} O_2(\text{gas}) \rightarrow 6 CO_2(\text{gas}) + 3 H_2O(\text{liquid})$ Benzene burns in oxygen according to the above equation. What is the volume of oxygen (at STP) needed for complete combustion of $39$ grams of liquid benzene?
$ 4.6\times {{10}^{22}} $ atoms of an element weigh $13.8\,g$. The atomic weight of that element is
Which of the following has the smallest number of molecules?