Advertisements
Advertisements
प्रश्न
Write true or false :
No new substance is formed during a chemical reaction.
पर्याय
True
False
Advertisements
उत्तर
False
APPEARS IN
संबंधित प्रश्न
State whether the following statement is true or false. In case a statement is false, write the corrected statement.
Iron and rust are the same substances.
State whether the following statement is true or false. In case a statement is false, write the corrected statement.
Condensation of steam is not a chemical change.
Classify the following reaction as combination, decomposition, displacement, precipitation and neutralization. Also balance the equation.
\[\ce{NH3_{(g)} + HCl_{(g)} -> NH4Cl_{(s)}}\]
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Miscible liquids having slightly different boiling points can be separated by the
- evaporation
- distillation
- fractional distillation
- sedimentation
True or false
New substances are formed in a chemical change.
Give an example of a reaction where the following are involved:
Close contact
State the type of reactions for the following represent and balance the ones that are not balanced.
Cl2 + 2KBr → 2KCl + Br2
Multiple choice:
Which of the following is not a characteristic of a chemical change?
Give an example of the following chemical changes.
A reaction involving
(i) Change of state
(ii) formation of precipitate
Name: A greenish-yellow gas.
Give a chemical test to distinguish between the following gases.
HCl and H2S
Give balanced equation for the following conversion affected by heat alone on the substance:
Copper carbonate to copper oxide
Complete the table given below.
| Heat on iodine crystals | Colour of vapours evolved |
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Zinc carbonate.
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Calcium hydroxide.
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.
Two chemical species X and Y combine together to form a product P which contains both X and Y
\[\ce{X + Y -> P}\]
X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following concerning the species X, Y and P are correct?
(i) P is a compound
(ii) X and Y are compounds
(iii) X and Y are elements
(iv) P has a fixed composition
Classify the following as physical or chemical properties
Zinc dissolves in hydrochloric acid with the evolution of hydrogen gas.
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 |
When milk is mixed with coffee decoction, the colour of milk and decoction changes due to ______.
