Q.36:- Chlorine is prepared in the laboratory by treating manganese dioxide (MnO2) with aqueous hydrochloric acid according to the reaction 4HCl (aq) + MnO2(s) → 2H2O(l) + MnCl2(aq) + Cl2(g) How…
Q.36:- Chlorine is prepared in the laboratory by treating manganese dioxide (MnO2) with aqueous hydrochloric acid according to the reaction 4HCl (aq) + MnO2(s) → 2H2O(l) + MnCl2(aq) + Cl2(g) How…
Q.35:- Calcium carbonate reacts with aqueous HCl to give CaCl2 and CO2 according to the reaction, CaCO3 (s) + 2HCl (aq) → CaCl2(aq) + CO2(g) + H2O(l) What mass of CaCO3 is…
Q.34:- A welding fuel gas contains carbon and hydrogen only. Burning a small sample of it in oxygen gives 3.38 g carbon dioxide , 0.690 g of water and no other products. A…
Q.33:- Calculate the number of atoms in each of the following (i) 52 moles of Ar (ii) 52 u of He (iii) 52 g of He. Answer:- (i) 1 mol of Ar…
Q.32:- Use the data given in the following table to calculate the molar mass of naturally occuring argon isotopes: Isotope Isotopic molar mass …
Q.31:- How many significant figures should be present in the answer of the following calculations? (i) 0.02856×298.15×0.112/0.5785 (ii) 5 × 5.364 (iii) 0.0125 + 0.7864 + 0.0215 Answer:- (i) Least precise…
Q.30:- What will be the mass of one 12C atom in g ? Answer:- 1 mol of 12C atoms = 6.022×1023 atoms = 12g ∴ Mass of 1 atom 12C = 12/6.022×1023 g =…
Q.29:- Calculate the molarity of a solution of ethanol in water in which the mole fraction of ethanol is 0.040 (assume the density of water to be one). Answer:- Mole…
Q.28:- Which one of the following will have largest number of atoms? (i) 1 g Au (s) (ii) 1 g Na (s) (iii) 1 g Li (s) (iv) 1 g of…
Q.27:- Convert the following into basic units: (i) 28.7 pm (ii) 15.15 pm (iii) 25365 mg Answer:- (i) 1 pm = 10-12 m 28.7 pm = 28.7×10-12 m = 2.87×10-11 m (ii) 1 pm = 10-12 m ∴15.15…