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

0.2 g atom of silicon combine with 21.3 g of chlorine. Find the empirical formula of the compound formed.

In a compound of magnesium (Mg = 24) and nitrogen (N = 14), 18 g of magnesium combines with 7g of nitrogen.

Deduce the simplest formula by answering the following questions:

1. How many gram-atoms of magnesium are equal to 18g?
2. How many gram-atoms of nitrogen are equal to 7g of nitrogen?
3. Calculate the simple ratio of gram-atoms of magnesium to gram-atoms of nitrogen and hence the simplest formula of the compound formed.

Give the empirical formula of C₆H₁₈O₃

112 cm³ of H₂S(g) is mixed with 120 cm³ of Cl₂(g) at STP to produce HCl(g) and sulphur(s). Write a balanced equation for this reaction and calculate

1. the volume of gaseous product formed.
2. composition of the resulting mixture.

A compound is formed by 24 g of X and 64 g of oxygen. If the atomic mass of X = 12 and O = 16, calculate the simplest formula of the compound.

Silicon (Si = 28) forms a compound with chlorine (Cl = 35.5) in which 5.6 g of silicon combines with 21.3 g of chlorine. Calculate the empirical formula of the compound.

A compound has the following percentage composition by mass: carbon 14.4%, hydrogen 1.2% and chlorine 84.5%. Determine the empirical formula of this compound. Work correctly to 1 decimal place. (H = 1; \[\ce{C}\] = 12; \[\ce{Cl}\] = 35.5)

The reaction: \[\ce{4N2O + CH4 -> CO2 + 2H2O + 4N2}\] takes place in the gaseous state. If all volumes are measured at the same temperature and pressure, calculate the volume of dinitrogen oxide (N₂O) required to give 150 cm³ of steam.

The volumes of gases A, B, C and D are in the ratio, 1 : 2 : 2 : 4 under the same conditions of temperature and pressure.

1. Which sample of gas contains the maximum number of molecules?
2. If the temperature and pressure of gas A are kept constant, then what will happen to the volume of A when the number of molecules is doubled?
3. If this ratio of gas volume refers to the reactants and products of a reaction, which gas law is being observed?
4. If the volume of A is actually 5.6 dm³ at STP, calculate the number of molecules in the actual Volume of D at STP (Avogadro's number is 6 × 10²³).
5. Using your answer from (iv), state the mass of D if the gas is dinitrogen oxide (N₂O).

Write the balanced equation for the reaction of dilute hydrochloric acid with the following:

Iron

Write the balanced equation for the reaction of dilute hydrochloric acid with the following:

Sodium hydrogen carbonate

Write the balanced equation for the reaction of dilute hydrochloric acid with the following:

Iron (II) sulphide

Write the balanced equation for the reaction of dilute hydrochloric acid with the following:

Magnesium sulphite

Write observation:

Lead nitrate solution is mixed with dilute hydrochloric acid and heated.

Write observation:

A small piece of zinc is added to dilute hydrochloric acid.

Lead nitrate decomposes on heating to give ______.

X, Y and Z are three crystalline solids that are soluble in water and have a common anion.

To help you to identify X, Y and Z, you are provided with the following experimental observations. Copy and complete the corresponding inferences in (a) to (e).

1. A reddish-brown gas is obtained when X, Y and Z are separately warmed with concentrated sulphuric acid and copper turning added to the mixture.
   INFERENCE 1: The common anion is the ______ ion.
2. When X is heated, it melts and gives off only one gas which re-lights a glowing splint.
   INFERENCE 2: The cation in X is either ______ or ______.
3. The action of heat on Y produces a reddish-brown gas and yellow residue which fuses with a glass of the test tube.
   INFERENCE 3: The metal ion present in Y is the ______ ion.
4. When Z is heated, it leaves no residue. Warming Z with sodium hydroxide solution liberates a gas which turns moist red litmus paper blue.
   INFERENCE 4: Z contains the ______ cation.
5. Write the equations for the following reactions:
   1. X and concentrated sulphuric acid (below 200°C). (One equation only for either of the cations given in INFERENCE 2)
   2. The action of heat on Y.
   3. Concentrated nitric acid is added to copper turnings kept in a beaker.

Write the equation for the reaction of dilute nitric acid with copper.

Explain why only all-glass apparatus should be used for the preparation of nitric acid by heating concentrated sulphuric acid and potassium nitrate.

Explain why nitric acid is kept in a reagent bottle for a long time.