NEET Chemistry MCQs

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 compound contains 28% nitrogen and 72% of a metal by weight. Three atoms of metal combine with two atoms of nitrogen. If the atomic weight of nitrogen is 14, the atomic weight of the metal is:

A nitrogen oxide contains 30.43% nitrogen by mass. Which of the following could be its molecular formula?

A hydrated salt of magnesium sulfate, $MgSO_4 \cdot xH_2O$, contains 51.2% water by mass. What is the value of 'x' in the formula?

A sample of hydrated copper sulfate weighs 25g. After heating to remove the water of crystallization, the anhydrous copper sulfate weighs 16g. What is the percentage of water of crystallization in the original sample?

A 1.00 g sample containing $BaCl_2\cdot2H_2O$ is heated to a constant mass of 0.835 g. What was the mass percent of barium in the original sample?

A hydrocarbon contains 85.7% carbon. Its molecular mass is 42. The molecular formula of the compound is:

An organic compound contains 40% carbon, 6.67% hydrogen, and 53.33% oxygen. Its vapour density is 30. What is its molecular formula?

A compound contains 40% carbon, 6.67% hydrogen, and 53.33% oxygen. Its empirical formula is:

What is the empirical formula of a compound containing 80% carbon and 20% hydrogen?