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

What volume of air (containing 20% O₂ by volume) will be required to burn completely 10 cm³ of methane and acetylene?

\[\ce{CH4 + 2O2 → CO2 + 2H2O}\]

\[\ce{2C2H2 + 5O2 -> 4CO2 + 2H2O}\]

LPG has 60% propane and 40% butane: 10 litres of this mixture is burnt. Calculate the volume of carbon dioxide added to atmosphere.

\[\ce{C3H8 + 5O2 → 3CO2 + 4H2O}\]

\[\ce{2C4H10 + 13O2 → 8CO2 + 10H2O}\]

200 cm³ of CO₂ is collected at STP when a mixture of acetylene and oxygen is ignited. Calculate the volume of acetylene and oxygen at STP. in original mixture.

\[\ce{2C2H2_{(g)} + 5O2_{(g)} → 4CO2_{(g)} + 2H2O_{(g)}}\]

Explain the term empirical formula.

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 ______.