NEET Questions

A mixture of $CaCO_3$ and $MgCO_3$ weighing 1.84 g on heating leaves a residue weighing 0.96 g. If the percentage by mass of $CaCO_3$ in the original mixture is x%, what is the value of x/2?

A 20 L vessel contains 0.1 mole of $O_2$ at 300 K. $O_3$ is prepared in the vessel by subjecting $O_2$ to silent electric discharge till the volume is reduced to 15 L at 300K. What is the number of moles of $O_3$ formed?

A metal M forms a volatile carbonyl complex $M(CO)_x$. 0.525g of this complex is heated in a closed vessel of volume 250 mL at $50^\circ C$. The pressure inside the vessel after complete decomposition of the complex is 746 Torr. If the gas constant R is 0.0821 L atm $K^{-1} mol^{-1}$, what is the value of x in the formula $M(CO)_x$? (Assume the metal M does not contribute significantly to the pressure)

A mixture of $CO$ and $CO_2$ weighing 1.12 g is treated with an excess of red hot $CuO$. The $CO$ is converted to $CO_2$. The total weight of $CO_2$ produced is 1.6 g. What was the weight percentage of $CO$ in the original mixture?

10 g of a metal oxide on strong heating gave 6.4 g of metal. If the formula of the metal oxide is $M_2O_3$, what is the atomic mass of the metal M?

Two elements X and Y combine to form two compounds $XY_2$ and $X_2Y_3$. If 0.05 moles of $XY_2$ weighs 5 g and 0.10 moles of $X_2Y_3$ weighs 20 g, find the atomic masses of X and Y.

A sample of hydrated copper sulfate ($CuSO_4 \cdot xH_2O$) weighs 25 g. Upon heating to drive off all the water, the anhydrous copper sulfate ($CuSO_4$) remaining weighs 16 g. What is the value of 'x' (the number of water molecules of crystallization)?

A hydrocarbon contains 82.76% carbon by mass. If 0.90 g of the hydrocarbon occupies a volume of 390 $cm^3$ at STP, what is its molecular formula?

A compound containing only carbon, hydrogen, and oxygen has a molar mass of approximately 90 g/mol. Combustion analysis of 0.405 g of the compound produces 0.54 g $CO_2$ and 0.27 g $H_2O$. If the compound's empirical formula is the same as its molecular formula, what is the number of oxygen atoms in one molecule of the compound?

Two organic compounds X and Y have the same empirical formula $CH_2O$. Compound X has a molar mass of 30 g/mol while compound Y has a molar mass of 90 g/mol. If 0.3 moles of X contains the same number of oxygen atoms as 'm' grams of Y, what is the value of 'm'?