When a lot of dry powder of a substance X is released over a fire, the fire gets extinguished.
(a) Name the substance X.
(b) How does this substance extinguish the fire?
(c) Name another substance which behaves like X.
(a) Sodium bicarbonate (sodium hydrogen carbonate)
(b) The heat of fire decomposes sodium bicarbonate to produce carbon dioxide gas. This carbon dioxide covers the fire like a blanket and cuts off the supply of fresh air to the burning substance. Due to this, the fire gets extinguished.
(c) Potassium bicarbonate (or Potassium hydrogen carbonate)
Related Articles
- (a) What is “baking powder”? How does it make the cake soft and spongy?(b) In addition to sodium hydrogencarbonate, baking powder contain a substance X. Name the substance. What is the role of substance X in the baking powder?
- A lot of dry powder of one of the following chemicals can be released over a fire to extinguished it. This chemical is:plaster of Parisbaking sodawashing sodabitumen
- When the concentrated aqueous solution of substance X is electrolysed, then NaOH, Cl2 and H2 are produced. Name the substance X. What is the special name of this process?
- A substance X is added to LPG cylinders while filling so as to make the detection of leakage of LPG from the cylinder easy.(a) Name the substance X. (b) How does substance X make the detection of leakage of LPG easy?
- A solution of a substance ‘X’ is used for white washing.(i) Name the substance ‘X’ and write its formula.(ii) Write the reaction of the substance ‘X’ named in (i) above with water.
- A substance X which is used as an antacid reacts with dilute hydrochloric acid to produce a gas Y which is used in one type of fire-extinguisher. Name the substance X and gas Y. Write a balanced equation for the chemical reaction which takes place.
- There are three substances X, Y and Z. The substance X does not have a fixed melting point or boiling point and it still shows the inpidual properties of its constituents. The substance Y is a pure substance which occurs in nature as such. The substance Y has a fixed melting point and boiling point but it cannot be broken down into simpler substances by any chemical means. The substance Z is also a pure substance whose properties are entirely different from those of its constituents. The substance Z can however, be divided by electrolysis into two substances which belong to the same class of substances as Y.(a) What type of substance could X be? Name one substance like X.(b) What type of substance could Y be? Name one substance like Y.(c) What type of substance could Z be? Name one substance like Z.(d) Which process involves absorption or release of an appreciable amount of energy : formation of substance X or formation of substance Z?(e) Name the three groups into which all the substances like Y are divided on the basis of their properties.
- A silvery-white metal X taken in the form of ribbon, when ignited, burns in air with a dazzling white flame to form a white powder Y. When water is added to powder Y, it dissolves partially to form another substance Z.(a)What could metal X be? (b) What is powder Y? (c) With which substance metal X combines to form powder Y? (d) What is substance Z? Name one domestic use of substance Z? (e)Write a balanced chemical equation of the reaction which takes place when metal X burns in air to form powder Y.
- There are four substances W, X, Y, and Z. The substance W is a dark violet solid having diatomic molecules. A solution of W in alcohol is used as a common antiseptic C. The substance X is a white solid which is usually recovered from seawater on a large scale. The substance Y is a white solid which is insoluble in water and used in the form of small balls for the safe storage of woolen clothes. The substance Z is yet another white solid which is used in making commonly used dry cells.(a) Name (i) W (ii) X (iii) Y and (iv) Z.(b) Out of W, X, Y, and Z, which substance/substances can undergo sublimation?(c) Which substance is organic in nature?(d) What is the name of substance C?(e) Which substance belongs to the halogen family?
- Fill in the blanks.(a) A ……….. process in which a substance reacts with ……….. to give off heat is called combustion.(b) When the clothes of a person catch ………… the person is covered with a …………… to extinguish fire.(c) The ………….. temperature at which a substance catches fire is called its ………….. temperature.(d) The substances which gave very ………….. ignition temperature and can easily catch fire with a flame are called …………. substances.(e) The substances which vaporise during …………….. give flame.
- How does pouring water extinguish a fire?
- The gland X which is located just below the brain in the human head secretes a chemical substance Y which controls the development of bones and muscles in the body of a person. Secretion of too little of substance Y as well as the secretion of too much of substance Y by the gland X leads to abnormal development of the body of a person.(a) Name the gland X.(b) What is the chemical substance Y?(c) What happens if too little of substance Y is secreted?(d) What happens if too much of substance Y is secreted?(e) Name the system of glands in the human body of which gland X is a part.
- The substance X normally exists in a physical state which can flow easily but does not fill its vessel completely. It also turns anhydrous copper sulphate blue. When substance X is cooled excessively, it changes into a substance Y which has a fixed shape as well as a fixed volume. If, however, substance X is heated strongly, it changes into a substance Z which has neither a fixed shape nor a fixed volume.(a) Name the substances (i) X (ii) Y and (iii) Z.(b) What is the process of conversion of X into Y known as?(c) At which temperature X gets converted into Y?(d) What is the process of conversion of X into Z known as?(e) At which temperature X gets converted into Z?
- A solid substance P which is very hard is used in the construction of many buildings, especially flooring. When substance P is heated strongly, it decomposes to form another solid Q and a gas R is given out. Solid Q reacts with water with the release of a lot of heat to form a substance S. When gas R is passed into a clear solution of substance S, then a white precipitate of substance T is formed. The substance T has the same chemical composition as starting substance P.(a) What is substance P? Write its common name as well as chemical formula.(b)What is substance Q?(c)What is gas R?(d)What is substance S? What is its clear solution known as?(e)What is substance T? Name any two natural forms in which substance T occurs in nature?
- When does a substance start burning?
Kickstart Your Career
Get certified by completing the course
Get Started
Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies