Advertisements
Advertisements
Question
Complete and balance the following chemical equations
Na + H2 O →
Solution
\[\ce{Na + H2O→2NaOH + H2↑}\]
APPEARS IN
RELATED QUESTIONS
Changes in which new substances are formed are called ______ changes.
Define; catalyst.
What do you observe when Iron nail is kept in copper sulphate solution for sometime.
Give reason.
Wasp sting is treated with vinegar.
TRUE \ FALSE
Positively charged electrode is called the anode. True or false ?
Fill in the blank
A new substance is always formed in a _______ change.
A chemical equation is a statement that describes a chemical change in terms of
Choose the correct option from the bracket and explain the statement giving a reason.
(Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition)
Addition of an aqueous solution of ZnSO4 to an aqueous solution of BaCl2 is an example of ______ reaction.
Write the chemical reaction where the following changes are observed.
Colour change is noticed
Define:
Photochemical reaction
Give one example
Complete and balance the following reaction:
\[\ce{CuCO3 ->[\Delta]}\]
Complete and balance the following reaction:
\[\ce{Pb(NO3)2 ->[\Delta]}\]
Complete and balance the following reaction:
\[\ce{NH3 + O2 ->[\Delta]}\]
State the original colour of the following substance and colour of residue obtained after heating.
Ammonium dichromate
What do you observe when Cobalt chloride paper is introduced in water vapour.
Name the following:
The type of change physical or chemical involved – ‘during respiration in human beings’.
A chemical reaction is often accompanied by external indications or characteristics.
Differentiate between the following:
Neutralization reaction and a precipitation reaction.
What is the role of a catalyst in a chemical reaction?
A reaction between an acid and a base is called ______.
______ 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.
Iron and rust are the same substances.
Match the following:
Column I | Column II | ||
1. | Burning of coal | a. | Rusting |
2. | Painting of a surface | b. | Evaporation |
3. | Dipping iron in the water | c. | Chemical change |
4. | Salt from seawater | d. | Prevention of rusting |
Write a note on the following:
Fermentation
Photosynthesis is a chemical charge. Justify your answer.
Why is spoiling food a chemical change?
When carbon dioxide is passed through lime water ______.
What are the chemical reactions that occur in everyday life?