The Mole & the Avogadro Constant
1. Separate: Chemistry and Extended Only
A substance was analysed and found to contain 26.57 % potassium, 35.36 % chromium, and 38.07 % oxygen by mass.
What is the empirical formula of the substance?
Ai এর মাধ্যমে
১০ লক্ষ+ প্রশ্ন ডাটাবেজ
প্র্যাকটিস এর মাধ্যমে নিজেকে তৈরি করে ফেলো
উত্তর দিবে তোমার বই থেকে ও তোমার মত করে।
সারা দেশের শিক্ষার্থীদের মধ্যে নিজের অবস্থান যাচাই
Extended Only
Sulphur dioxide reacts with chlorine in an addition reaction to form sulphuryl chloride.
SO2 + Cl2 → SO2Cl2
8.0 g of sulphur dioxide was mixed with 14.2 g of chlorine. The mass of one mole of SO2Cl2 is 135 g. Calculate the mass of sulphuryl chloride formed by this mixture.
Calculate the number of moles of SO2 in the mixture = ..................
Calculate the number of moles of Cl2 in the mixture = ..................
Which reagent was not in excess? ...............................
How many moles of SO2Cl2 were formed = ...................
Calculate the mass of sulphuryl chloride formed = ............. g
Crystals of sodium sulphate-10-water, Na2SO4.10H2O, are prepared by titration.
25.0 cm3 of aqueous sodium hydroxide is pipetted into a conical flask. A few drops of an indicator are added. Using a burette, dilute sulphuric acid is slowly added until the indicator just changes colour. The volume of acid needed to neutralise the alkali is noted.
Suggest how you would continue the experiment to obtain pure, dry crystals of sodium sulphate-10-water.
Extended Only
9.12 g of anhydrous iron(II) sulfate was heated. Calculate the mass of iron(III) oxide formed and the volume of sulfur trioxide, at r.t.p., formed.
2FeSO4 (s) → Fe2O3 (s) + SO2 (g) + SO3 (g)
mass of one mole of FeSO4 = 152 g number of moles of FeSO4 used = _____________ number of moles of Fe2O3 formed = _____________ mass of one mole of Fe2O3 = _____________ g mass of iron(III) oxide formed = _____________ g number of moles of SO3 formed = _____________ volume of sulfur trioxide formed = _____________ dm3
This question has 5 part(s).
