IGCSE Chemistry Paper-1: Specimen Questions with Answers 87 - 89 of 99
Question number: 87
Question
Which of the following below figure is not an unsaturated hydrocarbon?
Choices
| Choice (4) | Response | |
|---|---|---|
a. |  Which is Not Unsaturated Hydrocarbon – Choice A | |
b. |  Which is Not Unsaturated Hydrocarbon – Choice B | |
c. |  Which is Not Unsaturated Hydrocarbon – Choice C | |
d. | All of the above | |
Answer
b.Explanation
Unsaturated hydrocarbons are hydrocarbons that have many covalent bonds between adjacent carbon atoms. Those with at least one carbon-to-carbon double bond are called alkenes and those with at least one carbon-to-carbon triple bond are called alkynes.
Question number: 88
Question
What is molarity?
Choices
| Choice (4) | Response | |
|---|---|---|
a. | Molarity is the number of moles of a substance per litre of solution. | |
b. | Molarity is is the number of moles of solute per kilogram of solvent. | |
c. | Question does not provide sufficient data or is vague | |
d. | All of the above | |
Answer
a.Explanation
Molarity is also known as molar concentration, is the number of moles of a substance per litre of solution. Solutions labelled with the molar concentration are denoted with a capital M. A 1.0 M solution contains 1 mole of solute per litre of solution.
Question number: 89
Question
A white precipitate is formed when sodium sulphate reacts with barium chloride. The substance formed is?
Reaction of Sodium Sulphate with Barium Chloride
Choices
| Choice (4) | Response | |
|---|---|---|
a. | Barium sulphate | |
b. | Sulphur chloride | |
c. | Potassium sulphate | |
d. | All of the above | |
Answer
a.Explanation
The white precipitate of BaSO4 is formed by the reaction of SO42-and Ba2+. The other product formed is sodium chloride which remains in the solution. The reaction is as follows
The white insoluble substance formed is known as a precipitate. Any reaction that produces a precipitate can be called a precipitation reaction.