JEE Main 2020 & NEET 2020: Important MCQs (with Answers) from CBSE 11th Chemistry NCERT Book - Chapter 1 Some Basic Concepts of Chemistry

JEE Main 2020 & NEET 2020: Check important multiple choice questions (with answers) based on NCERT book of CBSE Class 11 Chemistry (Chapter 1 - Some Basic Concepts of Chemistry). These questions are based on topics from which questions have been frequently asked in previous engineering and medical entrance exams like JEE Main & NEET. Here we have also provided answers to these questions. Students of CBSE Class 11 and students preparing for JEE Main 2020 & NEET 2020 are advised to attempt these questions and check their preparation level for the exam. These questions are also helpful for the students preparing for the upcoming CBSE 11th Chemistry exam 2020-21.

JEE Main 2020 & NEET 2020: Check Important Chemical Reactions from CBSE Syllabus & NCERT Textbooks

Important questions for JEE Main 2020 & NEET 2020from CBSE 11th Chemistry NCERT Book - Chapter 1 Some Basic Concepts of Chemistry 

Question: If the density of a solution is 3.12 g mL–1, the mass of 1.5 mL solution in significant figures is _______.

(i) 4.7g

(ii) 4680 × 10–3g

(iii) 4.680g

(iv) 46.80g

Answer: (i)

Question:  What will be the molality of the solution containing 18.25 g of HCl gas in 500 g of water?

(i) 0.1 m

(ii) 1 M

(iii) 0.5 m

(iv) 1 m

Answer: (iv)

Question: What will be the molarity of a solution, which contains 5.85 g of NaCl(s) per

500 mL?

(i) 4 mol L–1

(ii) 20 mol L–1

(iii) 0.2 mol L–1

(iv) 2 mol L–1

Answer: (iii)

Question: The number of atoms present in one mole of an element is equal to Avogadro number. Which of the following elements contains the greatest number of atoms?

(i) 4g He

(ii) 46g Na

(iii) 0.40g Ca

(iv) 12g He

Answer: (iv)

Question:  Which of the following statements about a compound is incorrect?

(i) A molecule of a compound has atoms of different elements.

(ii) A compound cannot be separated into its constituent elements by

physical methods of separation.

(iii) A compound retains the physical properties of its constituent elements.

(iv) The ratio of atoms of different elements in a compound is fixed.

Answer: (iii)

Question:  Which of the following reactions is not correct according to the law of

conservation of mass.

(i) 2Mg(s) + O2(g) ⎯→ 2MgO(s)

(ii) C3H8(g) + O2(g) ⎯→ CO2(g) + H2O(g)

(iii) P4(s) + 5O2(g) ⎯→ P4O10(s)

(iv) CH4(g) + 2O2(g) ⎯→ CO2(g) + 2H2O (g)

Answer: (ii)

Question: A measured temperature on Fahrenheit scale is 200 °F. What will this reading

be on the Celsius scale?

(i) 40 °C

(ii) 94 °C

(iii) 93.3 °C

(iv) 30 °C

Answer: (iii)

Question: If the density of a solution is 3.12 g mL–1, the mass of 1.5 mL solution in significant figures is ______.

(i) 4.7g

(ii) 4680 × 10–3g

(iii) 4.680g

(iv) 46.80g

Answer: (i)