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प्रश्न
Name the technique that you use if only the solid component of a solution is required.
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उत्तर
Evaporation.
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संबंधित प्रश्न
Write true or false
All pure substances have characteristic melting and boiling points.
Write the Chemical Name of the Following and Also Give Their Molecular Formulae:
Sand
Give two examples of Metalloids.
Define: Molecule
Answer the following question:
When iron is mixed with sulphur at room temperature, it does not form a compound. Why?
Tick (√) the correct alternative from the choice given for the following statement.
All pure substances have
Complete the statement with the correct words.
Acid’s are chemicals which are _____ in taste and derived from plants and ________.
Match the statements in List I – 1 to 10 correct answers in List II-A to J.
| List I | LIst II | ||
| 1 | Fluorine and chlorine | A | Nitrogen |
| 2 | A diatomic molecule | B | Boron |
| 3 | A molecule containing the elements hydrogen and oxygen. | C | Reactants |
| 4 | A metalloid - showing properties of both metals and non-metals. | D | Chemical Formula |
| 5 | The term used for the substances which take part in the chemical reaction | E | Halogens |
| 6 | The term represents a substance by means of symbols. | F | Water |
| 7 | The term used for the substances formed as a result of a chemical reaction | G | Nitric Acid |
| 8 | A compound containing one atom of zinc and two atoms of chlorine. | H | Products |
| 9 | The chemical name for nitrogen monoxide. | I | Phosphorus |
| 10 | A polyatomic molecule. | J | Zinc Chloride |
Select the correct answer from the choice given below.
An element which is a poor conductor of heat
Match the compounds in List I – 1 to 20 with their correct formulas from in List II-A to T.
| List I | List II | ||
| 1 | Hydrochloric acid | A | NaCI |
| 2 | Potassium Hydroxide | B | NaOH |
| 3 | Sulphuric Acid | C | KCI |
| 4 | Zinc Hydroxide | D | Ca(OH)2 |
| 5 | Sodium Chloride | E | CaS |
| 6 | Nitric Acid | F | CuSO4 |
| 7 | Calcium Hydroxide | G | CaCO3 |
| 8 | Carbonic Acid | H | NH4CI |
| 9 | Sodium hydroxide | I | HCI |
| 10 | Copper sulphate | J | ZnO |
| 11 | Potassium Chloride | K | HNO3 |
| 12 | Calcium Carbonate | L | H2CO3 |
| 13 | Magnesium Sulphide | M | MgS |
| 14 | Zinc Sulphate | N | MgO |
| 15 | aluminium Hydroxide | O | KOH |
| 16 | Sodium Carbonate | P | ZnSO4 |
| 17 | Calcium Sulphide | Q | Na2CO3 |
| 18 | Magnesium Oxide | R | H2SO4 |
| 19 | Zinc Oxide | S | AI(OH)3 |
| 20 | Ammonium Chloride | T | Zn(OH)2 |
Give a reason for the following statement:
Components in a mixture are present in varying proportions and not in a fixed proportion.
Select the correct answer from A, B, C, D & E for the statement given below :
A diatomic molecule.
Give a reason for the following statement :
The filter paper made into a cone & placed in a funnel for filtering out the solid particles in a solid-liquid mixture should be moistened before placing it.
Non-metal conducting electricity :______ :: Metal conducting electricity : Copper
State true of false. If false, give the correct statement.
Two different elements may have similar atoms.
Differentiate metals and non-metals.
Assertion: Air is a mixture of elements only.
Reason: Only nitrogen, oxygen and neon gases exist in air.
Classify the substances given in Fig. 2.2 into elements and compounds
Complete the table by writing the symbols of the following elements
| Element | Symbol |
| Aluminum | Al |
| Nickel | |
| Bromine | |
| Helium | |
| Magnesium |
