Why should a magnesium ribbon be cleaned before burning in air?

-

Ques 1: Why should a magnesium ribbon be cleaned before burning in air?


Ans 1: Magnesium is very reactive metal like (Na, C a, etc.). When it expose to air it reacts with oxygen to form a layer magnesium oxide (Mg O) on its surface. 


                Mg + O2→ 2 Mg O

This layer of magnesium oxide is quite stable and prevents further reaction of magnesium with oxygen. The magnesium ribbon is cleaned by sand paper to remove this layer so that the underlying metal can be used for the reaction.



««Chapter 1 NCERT Solution 

                                        Next question»»

Comments

Post a Comment

Popular posts from this blog

Test and Measurement in Sports Case Study Based Questions Chapter 6 Class 12 Physical education

-
 1. Mr. Lakshman, aged 65 years worked as a civil engineer in a construction company. He had to walk and climb a lot as part of his job. After retirement, he settled with his son spending time with his grandchildren. Now a days he is experiencing difficulty in doing certain chores which involves physical movement.  (i) Which of the following tests would you recommend to check Mr. Lakshman’s fitness? (a) Harvard step test  (b) Rikli & Jones test (c) AAHPER test (d) Rock port test (ii) How many series of tests are there in the prescribed fitness test for Mr. Lakshman? (a) 8  (b) 6 (c) 5  (d) 4 (iii) Chair sit & reach test is done to check ____________ (a) Agility (b) Speed (c) Flexibility (d) Strength (iv) Pick the odd one out. (a) Arm curl test (b) Chair stand test (c) 6 min walk test (d) Partial curl up (v) The 8 foot up &go test, as shown in the picture is performed to assess _________ (a) Agility (b) Endurance (c) Speed (d) Strength 2. (i) Both the...
Read more

2.0 gram of a metal burst in oxygen give 3.2 gram of its oxide. 1.42 gram of the same metal heat in steam give 2.27 gram of its oxide which toys shown by this data?

-
Ques : 2.0 gram of a metal burst in oxygen give 3.2 gram of its oxide. 1.42 gram of the same metal heat in steam give 2.27 gram of its oxide which toys shown by this data?  Ans : In the first compound, 3.2 gram of metal oxide contained 2.0 gram of metal 100 gram of metal oxide contained metal =2.0/3.2 × 100= 62.5 g :· % metal in first compound= 62.5% In the second compound, 2.27 gram of metal oxide contains metal = 1.42 gram 100 gram of metal oxide contains the metal= 1.42/2.27×100=62.55 gram :· % metal in first compound= 62.55% Thus, the percentage of metal in metal oxide obtained from to experiment is nearly same. Hence, the above data illustrate the law of constant composition.  <<   Previous                                                       Next   >>
Read more

Brain (Study - Encephology) || Brain Encephology || BRAIN IS DIVIDED INTO THREE PARTS WITH THE SUB DIVISIONS||

-
                                Brain                 (Study - Encephology ) # Brain is the highly specalised organ of the body. Brain develops by the enlargement of embryonic neural tube... It is presemt in the cranial cavity of the skull and forms about 98% of the central nervous system.. # Brain is protected by connective tissue membrane called MENINGES.. # In fishes, only one protective covering is present called MENINX PRIMITIVA.. # In amphibians, reptiles, birds, brain is covered by two meninges:  Inner- pia arachnoid and Outer - Duramater.. # In mammals three protective covering is present:  Inner - piamater ; Middle - arachnoid and Outer - durameter...   # Just below and above the arachnoid membrane space is present, called SUBARACHNOID and SUBDURAL respectively..  These space are filled with Cerebrospinal fluid protect the brain from...
Read more

NCERT Solutions Class 10 Science Chapter 8 || How do organism reproduce additional questions solution || Class 10 Chapter 8 Additional questions solution || Biology || Science ||

-
Image
Ques 1: What is the importance of DNA copying in reproduction?   Ans 1: DNA (Deoxyribonucleic acid) is the genetic material found in the chromosomes, present in the nucleus of the cell. The DNA (Deoxyribonucleic acid) is the information site for making proteins and each specific type of protein leads to the specific type of body design.  Thus, it is the DNA molecule that specifies the body design of an individual. Therefore, it can be concluded that it is the DNA that gets transferred from parents to their offsprings and makes them look similar.   Ques 2: Why is variation beneficial to the species but not necessarily for the individual?   Ans 2: Variations are beneficial to the species than individual because s sometimes for a species,  the environmental conditions change so drastically that their survival becomes difficult.   For example, if the temperature of water increases suddenly, then most of the bacteria living in that wate...
Read more