The decomposition of potassium chlorate `(KClO_3)` is a slow process. But the decomposition becomes fast in the presence of a black powder. Answer the following question : What is black powder?

The decomposition of potassium chlorate (KClO_3) is a slow process. But the decomposition becomes fast in the presence of a black powder. Answer the following question : Why does the use of black powder make the decomposition fast?

The decomposition of potassium chlorate (KClO_3) is a slow process. But the decomposition becomes fast in the presence of a black powder. Answer the following question : Can you name the substance which can slow down the decomposition of H_2O_2 ?

Answer the following question- What happen during the process of photosynthesis?

In an experiment to estimate the size of a molecule of oleic acid 1mL of oleic acid is dissolved in 19 mL of alcohol. Then 1 mL of this solution is diluted to 20 mL by adding alcohol. Now 1 drop of this diluted solution is placed on water in a shallow trough. The solution spreads over the surface of water forming one molecule thick layer. Now, lycopodium powder is sprinkled evenly over the film and its diameter is measured. Knowing the volume of the drop and area fo the film we can calculate the thickness of the film which will give us the size of oleic acid molecule. Read the passage carefully and answer the following questions : What is the role of lycopodium powder?

Rekhe observed that her mother placed shrinkled or dried vegetables in water before cutting these for cooking. After sometime, these vegetables looked fresh. Answer the following questions: What is the name of the process used and define it.

Read the given passage and answers following questions : The particles of colloidal solution possess electrical charge which is responsible for the stability of these solutions. The charge on colloidal particles arises because of selective adsorption of ions which are common with their own lattice. The presence of charge on colloidal particles can be determined with the help of phenomenon known as electrophoresis. However, when some electrolyte is added, the charge on the particles of, dispersed phase gets neutralized and precipitation takes place. This process is also called coagulation. The coagulation is given by Hardy Schulze rules. According to these rules the ions carrying the charge opposite to that of sol particles are effective and coagulating power of an electrolyte is directly proportional to the fourth power of the valency of the ion. Coagulation can also occur by mutual precipitation , by electrophoresis, by persistent dialysis or by heating or cooling. Answer the following questions : What happens to the charge of particles when electrolyte is added ?

Read the given passage and answers following questions : The particles of colloidal solution possess electrical charge which is responsible for the stability of these solutions. The charge on colloidal particles arises because of selective adsorption of ions which are common with their own lattice. The presence of charge on colloidal particles can be determined with the help of phenomenon known as electrophoresis. However, when some electrolyte is added, the charge on the particles of, dispersed phase gets neutralized and precipitation takes place. This process is also called coagulation. The coagulation is given by Hardy Schulze rules. According to these rules the ions carrying the charge opposite to that of sol particles are effective and coagulating power of an electrolyte is directly proportional to the fourth power of the valency of the ion. Coagulation can also occur by mutual precipitation , by electrophoresis, by persistent dialysis or by heating or cooling. Answer the following questions : Which electrolyte is most effective for coagulating Fe(OH)3 sol?

Given below is the diagram of a human ovum surrounded by a few sperms. Observe the diagram and answer the following questions. What is the role of zona pellucida in this process?

Zinc is a transition element and has many useful applications. The presence of zinc in trace amounts is essential in humans and many animals. Answer the following question : What is the role of zinc in the body of humans and animals?