Some Basic Concepts of Chemistry — practice questions
91 curated practice questions from Some Basic Concepts of Chemistry (Chemistry Class 11, CBSE) — 91 easy. Every question includes the final answer free; step-by-step worked solutions with a free account.
- What is the total number of electrons present in 1.6 g of methane?
- The weight of AgCl precipitated when a solution containing 5.85 g of NaCl is added to a solution containing 3.4 g of…
- What quantity of copper oxide will react with 2.80 L of hydrogen at NTP?
- A solution is prepared by adding 5 g of a solute ‘ X ’ to 45 g of solvent ‘ Y ’. What is the mass per cent of the…
- What mass of sodium chloride would be decomposed by 9.8 g of sulphuric acid if 12 g of sodium bisulphate and 2.75 g of…
- What will be the standard molar volume of He, if its density is 0.1784 g/L at STP?
- What will be the weight of CO having the same number of oxygen atoms as present in 22 g of CO 2 ?
- The density of a gas is 1.78 g L –1 at STP. The weight of one mole of gas is
- Which of the following statements about Avogadro’s hypothesis is correct?
- Molarity equation of a mixture of solutions of same substance is given by
- The final molarity of a solution made by mixing 50 mL of 0.5 M HCl, 150 mL of 0.25 M HCl and water to make the volume…
- A compound contains atoms X , Y and Z . The oxidation number of X is +2, Y is +5 and Z is –2. The possible formula of…
- The number of electrons which will together weigh one gram is
- An impure sample of silver (1.5 g) is heated with S to form 0.124 g of Ag 2 S. What was the per cent yield of Ag 2 S?
- 0.48 g of a sample of a compound containing boron and oxygen contains 0.192 g of boron and 0.288 g of oxygen. What will…
- What will be the molarity of the solution in which 0.365 g of HCl gas is dissolved in 100 mL of solution?
- Which of the following pairs illustrates the law of multiple proportions?
- At NTP, 1 L of O 2 reacts with 3 L of carbon monoxide. What will be the volume of CO and CO 2 after the reaction?
- Which of the following gases will have least volume if 10 g of each gas is taken at same temperature and pressure?
- 0.92 g of an organic compound was analysed by combustion method. The mass of the U-tube increased by 1.08 g. What is…
- Which of the following statements about the molecular mass is correct?
- A compound contains two elements ‘ X ’ and ‘ Y ’ in the ratio of 50% each. Atomic mass of ‘ X ’ is 20 and ‘ Y ’ is 40…
- Atomic masses of elements are usually fractional because
- What will be the molality of chloroform in the water sample which contains 15 ppm chloroform by mass?
- Which mode of concentration does not change with temperature?
- How much mass of sodium acetate is required to make 250 mL of 0.575 molar aqueous solution?
- For every one 37 Cl isotope there are three 35 Cl isotopes in a sample of chlorine. What will be the average atomic…
- Match the column I with column II and mark the appropriate choice. Column I Column II (A) Mass of H 2 produced when 0.5…
- What will be the molality of the solution made by dissolving 10 g of NaOH in 100 g of water?
- What is the mass of carbon dioxide which contains the same number of molecules as are contained in 40 g of oxygen?
- A gas has molecular formula (CH) n . If vapour density of the gas is 39, what should be the formula of the compound?
- Total number of atoms present in 34 g of NH 3 is
- 2.18 g of an organic compound containing sulphur produces 1.02 g of BaSO 4 . The percentage of sulphur in the compound…
- How many number of molecules and atoms (respectively) are present in 2.8 litres of a diatomic gas at STP?
- 2.82 g of glucose is dissolved in 30 g of water. The mole fraction of glucose in the solution is
- 4.28 g of NaOH is dissolved in water and the solution is made to 250 cc. What will be the molarity of the solution?
- How many moles of oxygen gas can be produced during electrolytic decomposition of 180 g water?
- The number of oxygen atoms present in 1 mole of oxalic acid dihydrate is
- 1 g of Mg is burnt in a closed vessel containing 0.5 g of O 2 . Which reactant is limiting reagent and how much of the…
- Choose the molecular formula of an oxide of iron in which the mass per cent of iron and oxygen are 69.9 and 30.1…
- An organic compound on analysis gave C = 54.2%, H = 9.2% by mass. Its empirical formula is
- Fill in the blanks with appropriate words given below: Molecular mass is the __________ of atomic masses of elements…
- A compound of magnesium contains 21.9% magnesium, 27.8% phosphorus and 50.3% oxygen. What will be the simplest formula…
- The statements for laws of chemical combinations are given below. Mark the statement which is not correct.
- The relative number of atoms of elements, ‘ X ’ and ‘ Y ’ in a compound is 0.25 and 0.5. The empirical formula of…
- Which of the following correctly represents 180 g of water? (i) 5 moles of water (ii) 10 moles of water (iii) 6.023 ×…
- The diameter of an oxygen molecule is 3 . The ratio of molecular volume to the actual volume occupied by the oxygen gas…
- 18.72 g of a substance ‘ X ’ occupies l.81 cm 3 . What will be its density measured in correct significant figures?
- What will be the number of hydrogen atoms in 8.5 g NH 3 ?
- Which of the following formulae is not correctly depicted?
- How many number of aluminium ions are present in 0.051 g of aluminium oxide?
- What volume of dioxygen is required for complete combustion of 2 volumes of acetylene gas at NTP?
- An organic compound gave 0.4655 g of CO 2 on complete combustion. If the mass of the compound taken was 0.2115 g, what…
- A mixture having 2 g of hydrogen and 32 g of oxygen occupies how much volume at NTP?
- The empirical formula of a compound is CH 2 O 2 . What could be its molecular formula?
- In an experiment, 2.4 g of iron oxide on reduction with hydrogen gave 1.68 g of iron. In another experiment, 2.9 g of…
- 0.2 g of an organic compound contains C, H and O. On combustion, it yields 0.15 g CO 2 and 0.12 g H 2 O. The percentage…
- What mass of hydrochloric acid is needed to decompose 50 g of limestone?
- If 40 g of CaCO 3 is treated with 40 g of HCl. Which of the reactants will act as limiting reagent?
- In a reaction container, 100 g hydrogen and 100 g Cl 2 are mixed for the formation of HCl gas. What is the limiting…
- The volume of water molecule is (Take, density of water is 10 3 kg m –3 and avogadro’s number = 6 × 10 23 mole –1 )
- A solution is made by dissolving 49 g of H 2 SO 4 in 250 mL of water. The molarity of the solution prepared is
- Given below are few statements. Mark the statement which is not correct.
- 0.46 g of an organic compound was analysed. The increase in mass of CaCl 2 U-tube was 0.54 g and potash bulb was 0.88…
- The following data are obtained when dinitrogen and dioxygen react together to form different compounds: Mass of…
- 4.88 g of KClO 3 when heated produced 1.92 g of O 2 and 2.96 g of KCl. Which of the following statements regarding the…
- In the following question, a statement of assertion is followed by a statement of reason. Mark the correct choice…
- Oxygen occurs in nature as a mixture of isotopes 16 O, 17 O and 18 O having atomic masses of 15.995 u, 16.999 u and…
- How many oxygen atoms will be present in 88 g of CO 2 ?
- Calcium carbonate decomposes on heating to give calcium oxide and carbon dioxide. How much volume of CO 2 will be…
- Chlorine gas is prepared by reaction of H 2 SO 4 with MnO 2 and NaCl. What volume of Cl 2 will be produced at STP if 50…
- How much mass of silver nitrate will react with 5.85 g of sodium chloride to produce 14.35 g of silver chloride and 8.5…
- HCl is produced in the stomach which can be neutralised by Mg(OH) 2 in the form of milk of magnesia. How much Mg(OH) 2…
- What volume of 5 M Na 2 SO 4 must be added to 25 mL of 1 M BaCl 2 to produce 10 g BaSO 4 ?
- Match the mass of elements given in column I with the no. of moles given in column II and mark the appropriate choice…
- Total number of electrons present in one mole of CO 2 will be
- A balanced equation for combustion of methane is given below: CH 4( g ) + 2O 2( g ) → CO 2( g ) + 2H 2 O ( g ) Which of…
- Which of the following statements best explains the law of conservation of mass?
- What volume of water is to be added to 100 cm 3 of 0.5 M NaOH solution to make it 0.1 M solution?
- How much copper is present in 50 g of CuSO 4 ?
- How much oxygen is required for complete combustion of 560 g of ethene?
- The mass of one mole of a substance in grams is called its
- 1.4 moles of phosphorus trichloride are present in a sample. How many atoms are there in the sample?
- How many grams of CaO are required to react with 852 g of P 4 O 10 ?
- The reference standard used for defining atomic mass is
- Which of the following statements illustrates the law of multiple proportions?
- Two elements ‘ P ’ and ‘ Q ’ combine to form a compound. Atomic mass of ‘ P ’ is 12 and ‘ Q ’ is 16. Percentage of ‘ P…
- In a mixture of gases, the volume content of a gas is 0.06% at STP. Calculate the number of molecules of the gas in 1 L…
- Iron can be obtained by reduction of iron oxide (Fe 3 O 4 ) with CO according to the reaction: Fe 3 O 4 + 4CO → 3Fe +…
- One atom of an element weighs 3.32 × 10 –23 g. How many number of gram atoms are there in 20 kg of the element?
- What is the concentration of copper sulphate (in mol L –1 ) if 80 g of it is dissolved in enough water to make a final…