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

Calculate the number of molecules in 12.8g of sulphur dioxide gas. Take Avogadro's number as 6 x 10²³.
[S = 32, 0 = 16 ]

Calculate the weight of one molecule of oxygen.

[Avogadro’s number = 6 × 10²³, O = 16 ]

Two oxides of a metal (M) have 20.12% and 11.19% oxygen. The formula of the first oxide is MO. Determine the formula of the second oxide.

A student puts his signature with graphite pencil. If the mass of carbon in the signature is 10^-12 g. Calculate the number of carbon atoms in the signature.

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

Given that the relative molecular mass of copper oxide is 80, what volume of ammonia (measured at STP) is required to completely reduce 120g of copper oxide? The equation for the reaction is :
3CuO + 2NH₃ → 3Cu + 3H₂O + N₂

Calculate the number of moles and number of molecules present in 1.4 g of ethylene gas. What is the volume occupied by the same amount of ethylene?

A sample of ammonium nitrate when heated yields 8.96 litres of steam (measured at STP)
NH₄NO₃ → N₂O + 2H₂O
What volume of dinitrogen oxide is produced at the same time as 8.96 L of steam?

A sample of ammonium nitrate when heated yields 8.96 litres of steam (measured at STP)
NH₄NO₃ → N₂O + 2H₂O
What mass of ammonium nitrate should be heated to produce 8.96L of steam?

A sample of ammonium nitrate when heated yields 8.96 litres of steam (measured at STP)
NH₄NO₃ → N₂O + 2H₂O
Determine the percentage of oxygen in the ammonium nitrate?

The equation for the burning of octane is:

\[\ce{2C8H18 + 25O2 -> 16CO2 + 18H2O}\]

How many moles of carbon dioxide are produced when one mole of octane burns?

Correct the following statement :
Equal masses of all gases under identical conditions contain the same number of molecules.

Calculate the mass of 0.1 mole of carbon dioxide.

[Atomic mass: S = 32, C = 12 and O = 16 and Avogadro's number = 6 × 10²³]

Complete the following calculations. Show working for complete credit :
Calculate the mass of calcium that will contain the same number of atoms as are present in 3.2 gm of Sulphur. [Atomic masses : S = 32, Ca = 40]

Which of the following would weight the least?
[Atomic masses : Ag = 108, N - 14, O = 16,C = 12]

Consider the following reaction and based on the reaction answer the questions that follow :
\[\ce{(NH4)2Cr2O7 ->[heat] N2(g) + 4H2O(g) + Cr2O3}\] 
Calculate :
(i) The quantity in moles of (NH₄)₂Cr₂O₇ if 63 gm of (NH₄)₂Cr₂O₇ is heated.
(ii) The quantity in moles of nitrogen formed.
(iii) The volume in litres or dm³ of N₂evolved at STP.
(iv) The mass in grams of Cr₂O₃ formed at the same time
[Atomic masses : H = 1, Cr=52, N=14]

Calculate the number of gram atoms in 4.6 grams of sodium (Na = 23)

A gas cylinder can hold 1 kg of hydrogen at room temperature and pressure.
(a) Find the number of moles of hydrogen present
(b) What weight of CO₂can the cylinder hold under similar conditions of temperature and pressure? (H = 1 C = 12, O = 16)
(c) If the number of molecules of hydrogen in the cylinder is X, calculate the number of CO₂ molecules in the cylinder with the same conditions of temperature and pressure.
(d) State the law that helped you to arrive at the above result.

Give reason for the following:
Carbon anodes are used in the electrolytic extraction of aluminium.

Give equation for the following conversion:  Ferric oxide to iron.