CHEMISTRY TOPICAL QUESTIONS AND ANSWERS

The empirical formula of a hydrocarbon is (CH2). It has a density of 0.001167g/cm3 at room temperature and pressure. (Molar gas volume at r.t.p is 24dm3)

13/10/2021

Comments

The empirical formula of a hydrocarbon is (CH₂). It has a density of 0.001167g/cm³ at room temperature and pressure. (Molar gas volume at r.t.p is 24dm³)

a) Determine the molecular formula of the hydrocarbon (3mks)

b) Draw the structural formula of the hydrocarbon (1mk)

c) Ethene gas burns in Oxygen to form Carbon (IV) oxide and water.

i) Write an equation for the reaction between ethane gas oxygen gas (1mk)

ii) 15cm³ of ethene gas were mixed with 50cm3 of oxygen gas and the mixture was ignited into complete combustion. Calculate the volume of excess unreacted gas (3mks)

d) What happens when ethene gas is bubbled through bromine water? (2mks)

Bromine water is decolourised
Ethene gas is unsaturated hydrocarbon

e) Give any two uses of ethene gas (2mks)

Uses of Ethene gas

Manufacture of ethanol
Manufacture of polythene
Ripening of fruits
Laboratory preparation of ethane -1,2-diol used as coolant
Manufacture of detergents

(award 1mk for any one correct)

Comments

Differentiate between empirical and molecular formula.

11/10/2021

Comments

Differentiate between empirical and molecular formula (2mks)

Empirical formula show the simplest whole number ration in which atoms combine to for a compound while molecular formula shows actual number of each kind of atoms present in a molecule of a compound.

Comments

The empirical formula of a hydrocarbon is (CH2). It has a density of 0.001167g/cm3 at room temperature and pressure. (Molar gas volume at r.t.p is 24dm3)

The empirical formula of a hydrocarbon is (CH₂). It has a density of 0.001167g/cm³ at room temperature and pressure. (Molar gas volume at r.t.p is 24dm³)

a) Determine the molecular formula of the hydrocarbon (3mks)

b) Draw the structural formula of the hydrocarbon (1mk)

c) Ethene gas burns in Oxygen to form Carbon (IV) oxide and water.

i) Write an equation for the reaction between ethane gas oxygen gas (1mk)

ii) 15cm³ of ethene gas were mixed with 50cm3 of oxygen gas and the mixture was ignited into complete combustion. Calculate the volume of excess unreacted gas (3mks)

d) What happens when ethene gas is bubbled through bromine water? (2mks)

e) Give any two uses of ethene gas (2mks)

Differentiate between empirical and molecular formula.

Differentiate between empirical and molecular formula (2mks)

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The empirical formula of a hydrocarbon is (CH2). It has a density of 0.001167g/cm3 at room temperature and pressure. (Molar gas volume at r.t.p is 24dm3)

The empirical formula of a hydrocarbon is (CH2). It has a density of 0.001167g/cm3 at room temperature and pressure. (Molar gas volume at r.t.p is 24dm3)

​a) Determine the molecular formula of the hydrocarbon (3mks)

b) Draw the structural formula of the hydrocarbon (1mk)

​c) Ethene gas burns in Oxygen to form Carbon (IV) oxide and water.

​i) Write an equation for the reaction between ethane gas oxygen gas (1mk)

ii) 15cm3 of ethene gas were mixed with 50cm3 of oxygen gas and the mixture was ignited into complete combustion. Calculate the volume of excess unreacted gas (3mks)

​d) What happens when ethene gas is bubbled through bromine water? (2mks)

​e) Give any two uses of ethene gas (2mks)

Differentiate between empirical and molecular formula.

​Differentiate between empirical and molecular formula (2mks)

Chemistry Topics

Archives

Author

The empirical formula of a hydrocarbon is (CH₂). It has a density of 0.001167g/cm³ at room temperature and pressure. (Molar gas volume at r.t.p is 24dm³)

a) Determine the molecular formula of the hydrocarbon (3mks)

c) Ethene gas burns in Oxygen to form Carbon (IV) oxide and water.

i) Write an equation for the reaction between ethane gas oxygen gas (1mk)

ii) 15cm³ of ethene gas were mixed with 50cm3 of oxygen gas and the mixture was ignited into complete combustion. Calculate the volume of excess unreacted gas (3mks)

d) What happens when ethene gas is bubbled through bromine water? (2mks)

e) Give any two uses of ethene gas (2mks)

Differentiate between empirical and molecular formula (2mks)