(English Medium) ICSE Class 9 - CISCE Question Bank Solutions for Chemistry

Calculate the relative molecular mass of CaSO₄ [Zn = 65, S=32, O = 16, Ca = 40, C = 12]

Calculate the percentage of phosphorus in calcium hydrogen phosphate Ca(H₂PO₄)₂ .

Calculate the percentage of phosphorus in calcium phosphate Ca₃(PO₄)₂.

Calculate the percentage composition of each element in Potassium chlorate KCIO₃.

Urea is a very important nitrogenous fertilizer. Its formula is CON₂H₄. Calculate the percentage of carbon in urea. (C = 12, O = 16, N = 14 and H = 1)

How does number of valence electrons vary on moving from left to right in the third period of a periodic table?

Sodium and aluminum have atomic numbers 11 and 13, respectively. They are separated by one element in the periodic table and have valencies 1 and 3 respectively. Chlorine and potassium are also separated by one element in the periodic table (their atomic numbers being 17 and 19, respectively) and yet both have valency 1. Explain.

Calculate the percentage composition of calcium chloride.

Calculate the percentage composition of calcium nitrate [Ca = 40 , Cl = 35.5 , N = 14 , O = 16]

What causes the temporary and permanent hardness of water?

Find the percentage of mass water in Epsom salt MgSO₄.7H₂O.

What do you understand by

Soft water

What do you understand by

Hard water

What do you understand by

Temporary hard water

What do you understand by

Permanent hard water

What are the causes for:

Temporary hardness

What are the causes for

Permanent hardness

What are the advantages of soft water.

What are the advantages of hard water.

Name the substance which makes water temporarily hard