Laws of Chemical Combination
Trending Questions
Q. Which of the following sets of compounds correctly illustrates the law of reciprocal proportions?
- P2O5, PH3, H2O
- P2O3, PH3, H2O
- N2O, NH3, H2O
- N2O5, NH3, H2O
Q. Arrange the following in order of increasing mass
(i) 3.0115×1023 molecules of white phosphorus (P4)
(ii) 10 moles of H2 gas
(iii) 1 g molecule of anhydrous Na2CO3
(iv) 33.6 L of CO2 gas at S.T.P
(i) 3.0115×1023 molecules of white phosphorus (P4)
(ii) 10 moles of H2 gas
(iii) 1 g molecule of anhydrous Na2CO3
(iv) 33.6 L of CO2 gas at S.T.P
- ii<i<iv<iii
- iii<vi<i<ii
- i<ii<iv<iii
- i<iv<iii<ii
Q. Sodium and oxygen combine to form two compounds of which one is Na2O. The percentage of sodium in the other compound is 59%. Calculate the molecular weight (u) of the compound.
Q. When 0.0976 g of magnesium was heated in air, 0.1627 g of magnesium oxide (MgO) was produced. What is the mass of oxygen needed to produce 0.1627 g of MgO?
- 0.0651 g
- 0.0561 g
- 0.0115 g
- 0.6051 g
Q. Which of the following sets of compounds correctly illustrates the law of reciprocal proportions?
- P2O3, PH3, H2O
- P2O5, PH3, H2O
- N2O5, NH3, H2O
- N2O, NH3, H2O
Q. Which of the following is not in accordance with Dalton’s atomic theory?
- Matter is made up of extremely small indivisible particles called atoms.
- Atoms of different elements may combine with each other in a fixed, simple, whole number ratio to form compounds.
- Atoms can neither be created nor be destroyed in a chemical reaction.
- Equal volume of all gases under similar conditions of temperature and pressure contain different number of molecules.
Q. Which of the following statements represents Avogadro’s hypothesis?
- Atoms of different elements may combine with each other in a fixed, simple, whole number ratio to form compounds
- Equal volumes of all gases under the same temperature and pressure conditions contain an equal number of atoms
- Equal volumes of all gases under the same conditions of temperature and pressure contain an equal number of particles
- Gases react together in volumes which bear a simple ratio to one another
Q. A 19.6 g of a given gaseous sample contains 2.8 g of molecules d=0.75 g L−1 11.2 g of molecules (d=3g L−1) and 5.6 g of molecules (d=1.5 g L−1). All density measurements are made at STP. Calculate the total number of molecules (N) present in the given sample. Report your answer in N×1023.
Assume Avogardro's number as 6×1023.
Assume Avogardro's number as 6×1023.
- 3
- 2
- 2.5
- 4
Q. One of the statements of Dalton’s atomic theory is given below: “Compounds are formed when atoms of different elements combine in a fixed ratio.” Which of the following laws is not related to this statement?
- Law of conservation of mass
- Law of definite proportions
- Law of multiple proportions
- None of these
Q. When x g of NaHCO3 is heated, 12.62 g of Na2CO3, 5.24 g of CO2 and 2.14 g of H2O were produced. What is x?
- 20.00 g
- 15.00 g
17.86 g- 12.64 g
Q. When 10 g of KHCO3 is heated, 6.31 g of K2CO3 and 1.07 g of H2O are produced. How many grams of CO2 will be produced?
- 2.14 g
- 1.07 g
- 2.62 g
- 1.14 g
Q. Which of the following is not in accordance with Dalton’s atomic theory?
- Matter is made up of extremely small indivisible particles called atoms.
- Atoms can neither be created nor be destroyed in a chemical reaction.
- Atoms of different elements may combine with each other in a fixed, simple, whole number ratio to form compounds.
- Equal volume of all gases under similar conditions of temperature and pressure contain different number of molecules.
Q. When 0.0976 g of magnesium was heated in air, 0.1627 g of magnesium oxide (MgO) was produced. What is the mass of oxygen needed to produce 0.1627 g of MgO?
- 0.0651 g
- 0.0561 g
- 0.0115 g
- 0.6051 g
Q. When 10 g of KHCO3 is heated, 6.31 g of K2CO3 and 1.07 g of H2O are produced. How many grams of CO2 will be produced?
- 2.14 g
- 1.07 g
- 2.62 g
- 1.14 g
Q. Sodium and oxygen combine to form two compounds of which one is Na2O. The percentage of sodium in the other compound is 59%. Calculate the molecular weight of the compound.
- 42
- 78
- 62
- 108
Q. A mixture of FeO and Fe3O4 when heated in air to constant weight gains 5% in its weight. The % of FeO in the sample is:(Give your answer upto one decimal only)
Q. Match the following, choosing one item from Column - X and the appropriate related item from Column - Y.
Column-XColumn-Y(p)Equal volumes of all gases containequal number of molecules at NTP.(i) Dalton's atomic theory(q)The atom is indestructible(ii) Law of conservation of mass(r)All pure samples of the compound contain the same elements combined in the same proportion of mass.(iii) Avogadro's law(s)Total mass before and after thechemical reaction is same.(iv) Gay-Lussac's law(t)Gases react in simple ratio of theirvolumes(v) Law of constant proportions
Column-XColumn-Y(p)Equal volumes of all gases containequal number of molecules at NTP.(i) Dalton's atomic theory(q)The atom is indestructible(ii) Law of conservation of mass(r)All pure samples of the compound contain the same elements combined in the same proportion of mass.(iii) Avogadro's law(s)Total mass before and after thechemical reaction is same.(iv) Gay-Lussac's law(t)Gases react in simple ratio of theirvolumes(v) Law of constant proportions
- (p – iii), (q – i), (r – v), (s – ii), (t – iv)
- (p – iii), (q – i), (r – v), (s – iv), (t – ii)
- (p – iii), (q – v), (r – i), (s – ii), (t – iv)
- (p – iii), (q – ii), (r – v), (s – i), (t – iv)