Exercise

Select an incorrect reason for separating components of a mixture.

Nisha made a cup of tea using milk, sugar, and a tea bag. While pouring the tea in the cup, she didn't use a strainer. Can you guess why? What acted as a sieve here?

If the component in a mixture shows the property given below, then which separation method should be adopted—

One is soluble and another is insoluble in water.

Samyak was wandering in a car with his brother. The car's AC temperature was kept at the lowest. As soon as he stepped out, he found that his eyeglasses which were clear a few moments before are now the ones with a faded view.

Could you guess the city in which Samyak is roaming around out of Kashmir and Kolkata and what does this situation tell about the climate of this place?

Natasha was carrying a bottle full of iron filings to her class. As she walked past the sand pit in her school, she slipped and fell. The iron filings fell on the ground and got mixed with sand. Amita, a friend of her who was standing there suggested Natasha to get a magnet and collect the iron fillings. 

Has Amita given the correct advice? What steps will you follow to collect the iron fillings? 

Saarika was travelling in a train with her father in the coastal regions of Kutch in Gujarat State. She noticed that there were shallow pits along the railway line filled with sea water. In some pits, there was a white powdery substance. She also noticed small mounds of white substance collected by the workers. Consider this white powdery substance to be X. Substance X dissolves in water. There must be some process of obtaining substance X. Consider the process to be Y.

Answer the following questions based on your understanding of the above:

(a) What do you think component X is?

(b) How is the white powdery substances obtained from sea water? Name the process Y.

(c) Mention some factors that help to increase the rate of process Y?

What is the advantage of using a switch in a circuit?

Two glass beakers (A and B) were taken and filled them with equal quantity of water. Now added a teaspoon full of salt in beaker A. Kept on adding one teaspoon of salt at a time. Recorded the number of teaspoons of salt that dissolved in beaker A. Now repeated the activity by adding teaspoon full of sugar in beaker B. Again recorded the number of teaspoons of full of sugar that was dissolved in beaker B.

Does the same quantity of water dissolve same amount of sugar and salt?