NEET Chemistry MCQs

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)?

If two elements A and B combine in different ratios to form two compounds, the masses of B that combine with a fixed mass of A are in a small whole number ratio. This is a statement of:

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?

Two vectors $\vec{A}$ and $\vec{B}$ have magnitudes A and B respectively. If the magnitude of their cross product is $\frac{AB}{\sqrt{2}}$, which of the following could be the angle between $\vec{A}$ and $\vec{B}$?

If $\vec{A} = 2\hat{i} + 3\hat{j} - \hat{k}$ and $\vec{B} = \hat{i} - \hat{j} + 2\hat{k}$, what is the unit vector perpendicular to both $\vec{A}$ and $\vec{B}$?