Advertisements
Advertisements
प्रश्न
What is meant by saying that metals are lustrous ?
Advertisements
उत्तर
Metals are said to be lustrous because of their property to shine.
APPEARS IN
संबंधित प्रश्न
Gases have definite volume but no definite shape.
Fill in the blank
Liquids have a definite ______
When a crystal of potassium permanganate is placed at the bottom of water in a beaker, the water in the whole beaker turns purple on its own, even without stirring. This is an example of :
Name a non-metal which is a good conductor of electricity.
What is the other name for impure substances ? Give two examples of impure substances.
Explain why, hydrogen and oxygen are considered elements whereas water is not considered an element.
Name a metal which is yellow in colour.
One of the following substances is neither a good conductor of electricity nor an insulator. This substance is :
21.5 g of sodium chloride dissolves in 60 g of water at 25°C. Calculate the solubility of sodium chloride in water at that temperature.
100 mL of water at room temperature of 25°C is taken in a beaker and a little of solid S is dissolved in it by stirring to obtain a solution X. More and more of solid S is added to the solution with constant stirring, while keeping the temperature of solution constant at 30°C. After some time it is observed that no more solid dissolves in water and at the same time some solid is also left undissolved at the bottom of the beaker.
- The contents of beaker are filtered through a filter paper to obtain solution Y in the form of a filtrate.
- What name is given to solutions like X ?
- What name is given to solutions like Y ?
- What will you observe if the solution Y at 30°C is cooled down to 10°C by keeping the beaker in crushed ice ? Why ?
- What term is used to denote the amount of solid dissolved in 100 grams of water in a solution lie Y ?
A carpenter wants to separate iron nails from saw-dust. Which method of separation should he choose ?
Name the process which can be used to recover salt from an aqueous salt solution.
With the help of a labelled diagram, describe the method of separating ammonium chloride from a mixture of ammonium chloride and common salt. Mention the difference in the properties of ammonium chloride and sodium chloride which has made this separation possible.
The liquid air has three components X, Y and Z whose boiling points are : –186°C, –183°C and –196°C,
respectively. When liquid air is fed into a tall fractional distillation column from near its bottom and warmed
up slowly :
(a) Which component will be collected from near the bottom of the fraction distillation column ? Why ?
(b) Which component will be collected from the top part of the fractional distillation column ? Why ?
(c) Which component will be collected from the middle part of the fractional distillation column ? Why ?
(d) What could the component X, Y and Z be ?
Select the correct answer from A, B, C, D & E for the statement given below:
An atom or group of atoms _________ having a resultant charge.
Complete the given analogy.
Murukku from hot oil: ______:: Coffee powder residue from decoction: ______
Diffentiate between absorption and adsorption.
The most reactive metal is ______.
Gas-solid is ______.
Define the term matter.
