(English Medium) ICSE Class 10 - CISCE Question Bank Solutions for Chemistry

Calculate the percentage of phosphorous in the fertilizer superphosphate, Ca(H₂PO₄)₂. [Ca = 40, H =1, P =31, O = 16] (Correct to 1 decimal place)

A metal M, forms a volatile chloride containing 65.5% Chlorine. If the density of the chloride relative to hydrogen is 162.5, find the molecular formula of the chloride. [M = 56, Cl = 35.5]

Samples of the gases O₂, N₂, CO₂ and CO under the same conditions of temperature and pressure contain the same number of molecules represented by X. The molecules of Oxygen, occupy V litres and have a mass of 8 g. Under the same conditions of temperature and pressure :
What is the mass of CO₂ in g?

Calculate the percentage of platinum in ammonium chloroplatinate (NH₄)₂PtCl₆.
[N = 14, H = 1, Pt = 195, Cl =35.5]
(Give your answer correct to the nearest whole number)

A flask contains 3.2g of sulphur dioxide. Calculate the following: The number of molecules of sulphur dioxide present in the flask.

The reaction of potassium permanganate (VII) with acidified iron (II) sulphate is given below:
2KMno₄ + 10FeSO₄ + 8H₂O → K₂SO₄ + 2MnSO₄ + 5Fe2(SO₄)₃ + 8H₂O
If 15.8g of potassium permanganate (VII) was used in the reaction, calculate the mass of iron (II) sulphate used in the above reaction.

When heated, potassium permanganate decomposes according to the following equation:

\[\ce{2KMnO4 -> \underset{solid residue}{K2MnO4 + MnO2} + O2}\]

Some potassium permanganate was heated in test tube. After collecting one litre of oxygen at room temperature, it was found that the test tube had undergone a loss in mass of 1.32 g. If one litre of hydrogen under the same conditions of temperature and pressure has a mass of 0.0825 g, calculate the relative molecular mass of oxygen.

When heated, potassium permanganate decomposes according to the following equation:

\[\ce{2KMnO4 -> \underset{solid residue}{K2MnO4 + MnO2} + O2}\]

Given that the molecular mass of potassium permanganate is 158 g, what volume of oxygen (measured at room temperature) would be obtained by the complete decomposition of 15.8 g of potassium permanganate? (Molar volume at room temperature is 24 litres). [K = 39, Mn = 55, O = 16]

Calculate the percentage of nitrogen in aluminium nitride. [Al = 27, N = 14]

What is the vapour density of ethylene? (Avogadro's number = 6 x 10²³; Atomic weight of C = 12, H = 1; Molar volume = 22.4 litres at STP)

Calculate the percentage of sodium in sodium aluminium fluoride (Na₃AIF₆).
[F = 19, Na = 23, Al = 27]

A compound 'X' consists of 4.8% of C and 95.2% of Br by mass.
If the vapour density of the compound is 252, what is the molecular formula of the compound?

A compound 'X' consists of 4.8% of C and 95.2% of Br by mass. 
Name the type of chemical reaction by which X can be prepared from ethane.

The equation for the burning of octane is:

\[\ce{2C6H18 + 25O2 -> 16CO2 + 18H2O}\]

If the relative molecular mass of carbon dioxide is 44, what is the mass of carbon dioxide produced by burning two moles of octane?

A certain gas 'X' occupies a volume of 100 cm³ at S.T.P. and weighs 0.5 g. Find its relative molecular mass.

4.5 moles of calcium carbonate are reacted with dilute hydrochloric acid.

1. Write the equation for the reaction.
2. What is the mass of 4.5 moles of calcium carbonate? (Relative molecular mass of calcium carbonate is 100).
3. What is the volume of carbon dioxide liberated at STP?
4. What mass of calcium chloride is formed? (Relative molecular mass of calcium chloride is 111).
5. How many moles of HCl are used in this reaction?

Calculate the volume of oxygen required for the complete combustion of 8.8 g of propane (C₃H₅).
(Atomic mass: C = 14, O = 16, H = 1, Molar Volume = 22.4 dm³ at STP.)

Give one word or phrase for the following:

The ratio of the mass of a certain volume of gas to the mass of an equal volume of hydrogen under the same conditions of temperature and pressure.

Give one word or phrase for the following:

Formation of ions from molecules.

Complete the following calculations. Show working for complete credit :
 If the empirical formula of a compound is CH and it has a vapour density of 13, find the molecular formula of the compound.