Some Basic Concepts In Chemistry Questions

26 Practice QuestionsStart Practicing Now

[Medium]In the reaction N₂ + 3H₂ → 2NH₃, if 28 g of N₂ is mixed with 8 g of H₂, the mass of NH₃ formed is: (N = 14, H = 1)...
[Medium]What volume of 0.5 M H₂SO₄ is required to prepare 250 mL of 0.1 M H₂SO₄ by dilution?...
[Easy]The number of significant figures in the measurement 0.002060 g is:...
[Hard]A mixture of 2.0 g of H₂ and 32.0 g of O₂ is ignited. According to the reaction 2H₂ + O₂ → 2H₂O, the mass of water formed and the gas remaining after ...
[Easy]The percentage of nitrogen by mass in urea (NH₂CONH₂) is approximately: (N = 14, H = 1, C = 12, O = 16)...
[Easy]Carbon reacts with oxygen to form two different oxides: CO and CO₂. In CO, the ratio of carbon to oxygen by mass is 3:4, and in CO₂ it is 3:8. This ob...
[Easy]The molality of a solution prepared by dissolving 9.0 g of glucose (C₆H₁₂O₆, molar mass = 180 g mol⁻¹) in 500 g of water is:...
[Hard]The equivalent weight of KMnO₄ when it acts as an oxidising agent in acidic medium is: (K = 39, Mn = 55, O = 16)...
[Medium]When 5.3 g of Na₂CO₃ reacts with excess HCl according to the equation Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂, the volume of CO₂ produced at STP is approxim...
[Medium]A sample of an oxide of iron contains 7.0 g of iron and 3.0 g of oxygen. If the atomic masses of Fe and O are 56 and 16 respectively, the empirical fo...
[Easy]At STP, the volume occupied by 2.00 g of H2 gas (M=2) is approximately:...
[Hard]Which pair of solutions contains the same number of moles of solute?...
[Easy]How many molecules of water are present in 0.25 mol of H2O?...
[Easy]How many moles of oxygen atoms are present in 5.0 g of CaCO3? (Atomic masses: Ca=40, C=12, O=16)...
[Medium]The limiting reagent in the reaction 2Al + 3Cl2 → 2AlCl3 when 10.0 g Al (M=27) reacts with 20.0 g Cl2 (M=71) is:...
[Easy]A hydrocarbon sample contains 75% carbon by mass and remainder hydrogen. Its empirical formula is (Atomic masses: C=12, H=1)...
[Easy]Which statement is correct regarding Avogadro's hypothesis?...
[Medium]Determine empirical formula of a compound with 52.17% C, 34.78% O and 13.04% H (Atomic masses: C=12, O=16, H=1)....
[Medium]A sample contains 3.011×10⁺23 atoms of an element. Its mass is 12 g. The element is:...
[Easy]A sample of methane contains 0.25 mol. How many hydrogen atoms are present?...
[Easy]If 4.4 g of CO2 contains x molecules, what is x? (Molar mass CO2=44 g mol⁻¹)...
[Easy]Which statement correctly defines molality?...
[Easy]0.50 mol of CaCO3 is heated strongly. How many liters of CO2 (at STP) are evolved? (CaCO3 → CaO + CO2)...
[Medium]When 9.0 g of aluminium reacts completely with oxygen, how many grams of Al2O3 are formed? (2Al + 3/2 O2 → Al2O3, M(Al)=27, M(Al2O3)=102)...
[Easy]The mass percent of nitrogen in NH4 NO3 (Atomic masses: N=14, H=1, O=16) is:...
[Medium]The density of a gas at STP is 1.25 g L⁻¹. Its molar mass is approximately:...