Bissoy.com
Doctors Medicines MCQs Q&A

Consider the following aspects of substances involved in a chemical reaction: A. Physical state of all the substances  B. Number of molecules of all substances  C. Number of atoms of each substance D. Sum of masses of all atoms of substances  Which of the above remain the same before and after a chemical reaction has taken place? 

Consider the following aspects of substances involved in a chemical reaction: A. Physical state of all the substances  B. Number of molecules of all substances  C. Number of atoms of each substance D. Sum of masses of all atoms of substances  Which of the above remain the same before and after a chemical reaction has taken place?  Correct Answer C and D

The correct answer is C and D.

Explanation:

  • Before and after the chemical reaction, the number of atoms is the same.
  • Atoms are rearranged to form different substances during a chemical reaction, but the total number of atoms and the types of atoms are the same before and after the reaction.
  • Chemical reactions are balanced by adding coefficients to ensure that the number of atoms of each element on both sides is the same.
  • A physical change, such as changing states or dissolving, does not result in the formation of a new substance, whereas a chemical change does.
  • According to the law of conservation of mass, matter cannot be created or destroyed, so the total quantity of matter, i.e., the total mass, remains constant before and after a change. As a result, the mass of the substances before and after a chemical change will be the same.

Related Questions

The following are the conditions for selecting list of a suitable candidates to be called for interview after the written test for the recruitment is conducted/organized for management - level persons for a multi - national company. For providing accounting services and sales the candidate must (a) be holding a graduation in basic science with 65% or above or B.E. degree with 55% and above marks (b) have passed the written test with 70% or above marks (c) the age must be in the group 25 to 30 years as on 1/4/18 (d) have experience in an accounting firms for three years and diploma in accounting with 60% or above marks (e)  be presently drawing CTC of 6 Lakhs per annum and above In case the applicant who satisfies all other terms above except 1) at (a) above, then be referred as Junior Accountant 2) at (d) & (e) above then be referred as Trainee - Accountant Satisfying all the above with experience of 5 years then the referred as senior-Accountant Satisfying all the above criteria (a - e) with CA/ICWA/MBA (Finance) then be referred as manager (Accounts) Read all the above information and answer the following question Praveen has done his Masters in physics. He has no experience in accounting neither diploma. He is ready to be on training for accounting after joining. For which position he may be referred
The following are the conditions for selecting a list of suitable candidates to be called for interview after the written test for the recruitment is conducted/ organized for management-level persons for a multi-national company. For providing accounting services and sales the candidate must (a) beholding graduation in basic science with 65% or above or B.E. degree with 55% and above marks (b) have passed the written test with 70% or above marks (c) the age must be in the group 25 to 30 years as on 1/4/18 (d) have experience in an accounting firm for three years and a diploma in accounting with 60% or above marks e) be presently drawing CTC 6 lakhs per annum and above In case the applicant who satisfies all other terms above except 1) at (a) above, then be referred to as Junior Accountant 2) at (d) & (e) above then be referred to as Trainee-Accountant Satisfying all the above with experience of 5 years then be referred to as senior-Accountant Satisfying all the above criteria (a-e) with CA/ICWA/MBA (Finance) then be referred to as manager (Accounts) Read all the above information and answer the following question   Praveen has done his Masters in physics. He has no experience in accounting neither diploma. He is ready to be on training for accounting after joining. For which position he may be referred.
The following are the conditions for selecting list of a suitable candidates to be called for interview after the written test for the recruitment is conducted/ organized for management-level persons of a multi-national company. For providing accounting services and sales the candidate must (a) be holding a graduation in basic science with 65% or above or B.E degree with 55% and above marks (b) have passed the written test with 70% or above marks (c) the age must be in the group 25 to 30 yrs as on 1/4/18 (d) have experience in an accounting firms for three yrs and diploma in accounting with 60% or above marks (e) be presently drawing CTC of 6 Lakhs per annum and above In case the applicant who satisfies all other terms above except 1) at (a) above, then be referred as Junior Accountant 2) at (d) & (e) above then be referred as Trainee-Accountant Satisfying all the above with experience of 5 yrs then be referred as senior-Accountant Satisfying all the above criteria (a-e) with CA/ ICWA/ MBA (Finance) then be refereed as manager (Accounts) Read all the above information and answer the following question: Radha Mohan has done her graduation in physics with 58% of marks. She has passed the written examination with 76% of marks. She is 27 yrs as on June 2018. She has the experience in the accounting company for four years with salary of 7 Lakhs per annum. She also has passed diploma in accounting with 61% of marks. She may be referred for the position of:
The following are the conditions for selecting list of a suitable candidates to be called for interview after the written test for the recruitment is conducted/ organized for management-level persons of a multi-national company. For providing accounting services and sales the candidates must (a) be holding a graduation in basic science with 65% or above or B. E degree with 55% and above marks (b) have passed the written test with 70% or above marks (c) the age must be in the group 25 to 30 years as on 1/4/18 (d) have experience in an accounting firms for three years and diploma in accounting with 60% or above marks (e) be presently drawing CTC of 6 Lakhs per annum and above In case the applicant who satisfies all other terms above except 1) at (a) above, then be referred as Junior Accountant 2) at (d) & (e) above then be referred as Trainee-Accountant Satisfying all the above with experience of 5 years then be referred as senior-Accountant Satisfying all the above criteria (a-e) with CA/ ICWA / MBA (Finance) then be refereed as manager (Accounts) Read all the above information and answer the following question Shravani has passed H. SC with 72% of marks. She has done diploma in accountancy with 62% of marks. She was working with an organization in the field of accounting in the field of accounting from 4 years and was drawing CTC of 6.5 Lakhs presently. She is 28yrs as on July 2018. She may referred for the position of:
Consider the given statement and decide which of the given assumption/s is/are implicit. Statement: Serials/soaps are a reason for developing negative tendencies in women. Assumptions: I: Newspapers highlight the negative aspects first and then, the positive aspects. II: The attention given to the negative aspects is much higher than that given to the positive aspects.
Which of the following is the correct definition of mole? (A) It is equal to the gram atomic mass of the substance (B) It contains 6.022 × 1020 atoms of the given substance (C) It is equal to the gram molecular weight of the substance (D) It contains 6.022 × 1023 molecules of the given substance
Consider the given statement and which of the given assumptions is (are) implicit.
Statement:
The serials/soaps are a reason for developing negative tendencies in women. Assumptions :
1. Newspapers highlight the negative aspects first than the positive aspects.
2. The attention for negative aspects is much higher than positive aspects
In a survey of 25 students, it was found that 15 had taken Mathematics, 12 had taken Physics and 11 had taken Chemistry, 5 had taken Mathematics and Chemistry, 9 had taken Mathematics and Physics, 4 had taken Physics and Chemistry and 3 had taken all the three subjects. Find the number of students who had taken both Physics and Chemistry but not Mathematics.
Each of the question below consists of a question and three statements number I, II and III given below it. You have to decide whether the data provided in the statement are sufficient to answer the question. If the bus is travelling from Surat to Ahmadabad and a car is travelling from Ahmadabad to Surat, then what is the distance between Surat and Ahmadabad? I. The speed of a car is 40% less than the speed of bus. Bus started at 9 am and car started at 10 am and they meet at 3 pm of the same day. II. After travelling for 1 hour, because of traffic average speed of bus is decreased by 20% and covers distance between Surat to Ahmadabad in 11 hours. Original speed of car is 20% less than original speed of bus and before crossing bus it covered 200 km if starts 1 hour later than bus. After crossing car, bus covers remaining distance in 5 hours. III. Speed of bus is 10 km/hr more than the speed of car and before crossing car ratio of distances covered bus and car in same time was 5 : 4. Time taken by car to cover the distance between Ahmadabad and Surat is 2 hours 15 minutes more than time taken by bus to cover the same distance.
In a survey of university students, 64 had taken Drama course, 94 had taken Dance course, 58 had taken a Singing course, 28 had taken Drama and singing course, 26 had taken Drama and dance course, 22 had taken Dance and singing course, and 14 had taken all the three courses. Find how many have taken only one course?