The largest number of molecules is in


Correct option is

36 g of water


Number of molecules present in 36 g of water


Number of molecules present in 28 g of CO   


Number of molecules present in 46 g of C2H5OH  


Number of molecules present in 54 g of N2O5  


Here NA is Avogadro’s number. Hence, 36 g of water contain the largest (2NA) number of molecules.



500 mL of NH3 contain  molecules at S.T.P. How many molecules are present in 100 mL of CO2 at S.T.P.? 



In the reaction, 4 NH3 + 5 O2 → 4 NO + 6 H2O,

when one mole of ammonia and one mole of oxygen are made to react to completion, then


An unknown element forms an oxide. What will be the equivalent weight of the element if the oxygen content is 20% by weight? 


A metal M of equivalent mass E forms an oxide of molecular formulaMxOy. The atomic mass of the metal is given by the correct equation


Which of the following methods of expressing concentration are independent of temperature?



Pressure is determined as force per unit area of the surface. The S.I unit of pressure, pascal, is as shown below:

                               1Pa = 1 Nm–2

 If mass of air at sea level is 1034g cm-2, calculate the pressure in pascal.


Determine the molecular formula of an oxide of iron in which the mass percent of iron and oxygen are 69.9 and 30.1 respectively. Given that the molar mass of the oxide is  (Atomic mass: Fe = 55.85, O = 16.00 amu)


A gaseous mixture contains oxygen and nitrogen in the ratio of 1:4 by weight. Therefore, the ratio of their number of molecules is


The total number of electrons in one molecule of carbon dioxide is


When the same amount of zinc is treated separately with excess ofsulphuric acid and excess of sodium hydroxide, the ratio of volumes of hydrogen evolved is