In this article, students who are preparing for JEE Main entrance examination 2018 will get a downloading link of a PDF containing a set of 30 questions from Chemistry in the form of solved practice paper based on the latest pattern of the examination.
About the practice paper:
1. There are 30 questions in this practice paper.
2. All questions are of objective type with single correct option.
3. Solutions of all the questions are explained in a very clear manner.
4. This practice paper is based on the latest syllabus of JEE examination.
5. In this paper, we have included questions from different level i.e., easy, moderate and tough.
6. In this paper, we have tried to include questions from each chapter of Chemistry.
After attempting this paper, students must revise all the concepts and theory where they have done the wrong answers.
Few sample questions from the Practice Paper are given below:
Q. Which of the following statement is true?
(a) In aqueous medium, HF is a stronger acid than HCI.
(b) HCIO4 is a weaker acid than HCIO3.
(c) HNO3 is a weaker acid than HNO2.
(d) H3PO5 is a weaker acid than H2SO3.
The order of acidic strength are:
Q. The reagent which does not react with both, acetone and benzaldehyde?
(a) Sodium hydrogen sulphite
(b) Phenyl hydrazine
(c) Fehling's solution
(d) Grignard reagent
Acetone and benzaldehyde both do not react with Fehling's solution. Fehling's solution react with ketone as acetone is an ketone while benzaldehyde is an aromatic aldehyde having absence of a-hydrogen.
Q. Which of the following acids is a vitamin?
(a) Aspartic and
(b) Ascorbic acid
(c) Adipic acid
(d) Saccharic acid
Ascorbic acid is the chemical name of vitamin C. While others are not vitamins aspartic acid is an amino acid. Adipic acid is a dicarboxylic acid having 8 carbon chain. Saccharic acid is a dicarboxylic acid obtained by oxidation of glucose using HNO3.
Q. Zone refining is based on the principle that
(a) impurities of low boiling metals can be separated by distillation.
(b) impurities are more soluble in molten metal than in solid metal.
(c) different components of a mixture are differently adsorbed on an adsorbent.
(d) vapours of volatile compound can be decomposed in pure metal.
Zone refining is based on the principal that the impurities are more soluble in molten state than in solid state of the metal A circular mobile heater fixed at one end of impure metal rod. The molten zone moves along with heater which is moved forward.
As the heater moves forward, the pure metal crystallises out of the melt and the impurities pass on into adjacent molten zone. The process is repeated several times and the heater is moved in the same ti r action.
At one end, impurities get concentrated. Tins end is cut off. e.g., germanium, silicon, gallium etc., are refined by this method