Advertisements
Advertisements
प्रश्न
Classify the following reaction into –
- Direct combination
- Decomposition
- Displacement
- Double decomposition
The reaction is – Molten zinc at high temperatures, burns in air to give zinc oxide.
उत्तर
Direct combination
\[\ce{2Zn + O2 -> 2ZnO}\]
APPEARS IN
संबंधित प्रश्न
Give one example of a combination reaction which is also exothermic.
What effect does an increase in concentration of H+ (aq.) in a solution have on the pH of solution?
Explain the terms with examples.
Combination reaction
Select the correct answer for the statement given below:
The product formed during direct combination reaction of carbon dioxide and water.
Combustion reactions are always ____________.
The respiration process during which glucose undergoes slow combustion by combining with oxygen in the cells of our body to produce energy is a kind of:
The chemical reaction between copper and oxygen can be categorized as ______.
The Salt Story
From: The New Indian Express 9 March 2021
The salt pans in Marakkanam, a port town about 120 km from Chennai are the third largest producer of salt in Tamil Nadu. Separation of salt from water is a laborious process and the salt obtained is used as raw materials for manufacture of various sodium compounds.
One such compound is Sodium hydrogen carbonate, used in baking, as an antacid and in soda acid fire extinguishers.
The table shows the mass of various compounds obtained when 1litre of sea water is evaporated.
| COMPOUND | FORMULA | MASS OF SOLID PRESENT /g |
| Sodium Chloride | NaCl | 28.0 |
| Magnesium Chloride | MgCl2 | 8.0 |
| Magnesium Sulphate | MgSO4 | 6.0 |
| Calcium Sulphate | CaSO4 | 2.0 |
| Calcium Carbonate | CaCO3 | 1.0 |
| TOTAL AMOUNT OF SALT OBTAINED | 45.0 | |
Which compound in the table reacts with acids to release carbon dioxide?
Read the text below and answer the questions that follow:
A small amount of hydrochloric acid was taken in a test tube. The test tube was heated. A glass rod was dipped in the ammonia solution and held on the top of the test tube. A white smoke was seen emanating from the tip of the glass rod.
- What must have happened?
- Which colour of gas is formed?
- Write the chemical equation for the reaction.
A clear solution of slaked lime is made by dissolving Ca(OH)2 in an excess of water. This solution is left exposed to air. The solution slowly goes milky as a faint white precipitate forms. Explain why a faint white precipitate forms, support your response with the help of a chemical equation.
