Five grams of each of the following gases at 87oC and 750 mm pressure are taken. Which of them will have the least volume?
5 g HF = 5/20 mol, 5 g HCl = 5/36.5 mol, 5 g HBr = 5/81 mol, 5 g HI=5/121 mol. Thus HI has least no. of moles and hence least volume.
The formula weight of an acid is 82.0 in a titration 100 cm3 of a solution of this acid containing 39.0 g of the acid per litre were completelyneutralised by 95.0 cm3 of aqueous NaOH containing 40 .0 g of NaOHper litre. What is the basicity of the acid?
An analysis of a pyrex glass showed 12.9% B2O3, 2.2% Al2O3, 3.8% Na2O, 0.4% K2O and remaining is SiO2. What is the ratio of Si to B atoms in the glass?
One litre of a gas is at a pressure of 10–6 mm of Hg at 25oC. How many molecules are present in the vessel?
27 g of Al (at mass = 27) will react with oxygen equal to
2.76 g of silver carbonate (at mass of Ag = 108) on being heated strongly yields a residue weighing
If 0.5 mol of BaCl2 is mixed with 0.2 mol of Na3PO4, the maximum number of moles of Ba3(PO4)2 that can be formed is
If 1021 molecules are removed from 200 mg of CO2, then the number of moles of CO2 left are
The number of gram molecules of oxygen in molecules is
The molecular weight of O2 and SO2 are 32 and 64 respectively. If onelitre of O2 at 15oC and 750 mm contains N molecules, the number of molecules in two litres of SO2 under the same conditions of temperature and pressure will be
Haemoglobin contains 0.33% of iron by weight. The molecular weight of haemoglobin is approximately 67200. The number of iron atoms (at wt. of Fe = 56) present in one molecule of haemoglobin is