For the reaction,


5 moles of X and 9 moles of Y will produce


Correct option is

4 moles of Z


In a chemical reaction, coefficient represents mole of that substance.  


This indicates 1 mole of X reacts with 2 moles of Y to form 1 mole of Z.

So, 5 moles of X will require 10 moles of Y. But we have taken only 9moles of Y.  

Hence, Y is in limiting quantity. Hence, we determine product from Y.

Thus, 5 moles of X react with 9 moles of Y to form 4 moles of Z.



An organic compound was analysed by Duma’s method. 0.45 g of the compound on combustion gave 48.6 ml nitrogen at 27oC and 756 mm pressure. Calculate the percentage of nitrogen.


An organic compound on analysis gave the data : 0.25 g of the compound on complete combustion gave 0.37 g of CO2 and 0.2 g of water.


0.2 g of an organic compound was analysed by Kjeldahl’s method. Ammonia evolved was absorbed in 60 ml N/5 H2SO4. Unused acid required 40 ml of N/10 NaOH for complete neutralisation. Find the percentage of nitrogen in the compound.


1.216 g of an organic compound was reacted under Kjeldahl’s method and ammonia evolved was absorbed in 100 ml N H2SO4. The remaining acid solution was made up to 500 ml by addition of water 20 ml of this dilute solution required 32 ml of N/10 caustic soda solution for complete neutralisation. Calculate the percentage of nitrogen in the compound. 


0.5264 g silver bromide is obtained from 0.5124 g of an organic compound. Calculate the percentage of bromine in the compound.


0.156 g of an organic compound on heating with fuming HNO3 and AgNO3 gives 0.235 g of AgI. Calculate the percentage of the iodine in the compound.


0.1170 g of an organic compound on heating with conc. HNO3 and silver nitrate in Carius furnace gave 0.42 g of AgCl. Find the percentage of chlorine in the compound.


On heating 0.32 g of an organic compound with concentrated nitric acid and barium chloride, 0.932 g barium sulphate was obtained. Calculate the percentage of sulphur in the given compound.


6 g of an organic compound containing oxygen is heated with graphite and carbon monoxide formed is quantitatively converted to 8.8 g CO2 on reaction with I2O5. Calculate percentage of oxygen in the compound.


The function of boiling the sodium extract with conc. HNO3 before testing for halogen is: