NEET Chemistry MCQs

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 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?

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

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'?

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 gaseous organic compound has an empirical formula $C_xH_y$. When 0.150 g of the compound is completely combusted, it produces 0.225 g of $CO_2$ and 0.090 g of $H_2O$. Given the vapor density of the compound is 29, what is the molecular formula?

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 has an empirical formula of CH and a molecular mass of 78 g/mol. What is its molecular formula?