Advertisements
Advertisements
Question
True or false
New substances are formed in a chemical change.
Options
True
False
Solution
True
APPEARS IN
RELATED QUESTIONS
Changes in which new substances are formed are called ______ changes.
How do the following help in bringing about a chemical change?
pressure.
How do the following help in bringing about a chemical change?
light.
Write the missing reactants and products and balance the equations.
................+ HCI `→` NaCI + `"H"_2"O"` + .........................
Give reason .
A person suffering from acidity is advised to take an antacid.
TRUE \ FALSE
Copper can displace iron from iron sulphate.
TRUE \ FALSE
Evaporation of water is a physical change. True or false ?
Fill in the blank
A new substance is always formed in a _______ change.
Differentiate between in Chemical reaction and chemical equation.
Write true or false :
Hydrogen sulphide has rotten egg smell .
What do you understand by precipitation reaction? Explain with examples.
Give a chemical test to distinguish between the following gases.
H2 and CO2
Select the correct answer for the following options:
The basic gas obtained when two gases react in presence of a catalyst and the reaction is exothermic.
Give balanced equation for the following conversion affected by heat alone on the substance:
Copper nitrate to nitrogen dioxide
State the following reaction represent oxidation or reduction.
\[\ce{H->H+}\]
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Calcium hydroxide.
True or False. If false, give the correct answer.
Taking a glass of water and freezing it by placing it in the freezer is a chemical change.
________ is a chemical substance which alters the speed of a chemical reaction.
Rusting of Iron: undesirable change:: Dead plants turn into manure: ______.
______ is a natural indicator.
Arrange the following statements in correct sequence:
- One side is water-loving and other water-hating molecules.
- When you agitate the cloth, the dirt is surrounded by many molecules and taken away from the cloth.
- The dirt surrounded by the detergent molecules floats in the water making it dirty.
- Finally, the cloth is clean.
- The detergent molecules have two sides.
- Water hating goes and joins with dirt and oil in the cloth while the water-loving joins with the water molecules.
On heating calcium carbonate gets converted into calcium oxide and carbon dioxide.
(a) Is this a physical or a chemical change?
(b) Can you prepare one acidic and one basic solution by using the products formed in the above process? If so, write the chemical equation involved.
State whether the following statements are true or false:
When a candle burns, both physical and chemical changes take place.
Iron benches kept in lawns and gardens get____________. It is a _________ change because a new _________ is formed.
Write word equations for two chemical reactions with the help of materials given in the box.
Air, copper sulphate, iron, vinegar, iron oxide, carbon dioxide, iron sulphate, copper, lime water, water
Give an example of a chemical reaction for each of the following situations:
A change in colour is observed.
Rusting of iron is ______.
When magnesium is burnt in the air, a new substance is formed which is ______.
How can we prevent rusting?
Write a note on the catalyst.