Advertisements
Advertisements
प्रश्न
How much water should be added to 15 grams of salt to obtain 15 per cent salt solution ?
Advertisements
उत्तर
To make the salt solution of 15% with 15 gm as the mass of the solute, the mass of the solvent must be 85 gm.
`"concentration" = "mass of solute"/"mass of solute + mass of solvent"xx 100`
Mass of solution = mass of solute + mass of solvent
Mass of the solvent = mass of the solution – mass of solvent
= 100 – 15 = 85 gm
Therefore, 85 gm of water should be added.
APPEARS IN
संबंधित प्रश्न
Give one difference between atoms and molecules.
What is meant by saying that metals are malleable and ductile?
What is meant by saying that non-metals are brittle ?
What are the two types of pure substances? Give one example of each type.
Classify the following into metals, non-metals and metalloids:
Silicon, Mercury, Diamond, Sulphur, Iodine, Germanium, Sodium, Carbon, Magnesium, Copper, Boron, Helium
Draw a flow-chart for the schematic representation of different types of matter.
One of the following substances is neither a good conductor of electricity nor an insulator. This substance is :
There is a large group of materials P which can be divided into three groups Q, R and S on the basis of their properties. The substances belonging to group Q can be solids, liquids or gases. The solids belonging to group Q are usually electrical insulators. Most of the substances of group R are solids which are good conductors of electricity. The substances belonging to group S are neither insulators like Q nor good conductors like R. The properties of S are intermediate between those of Q and R.
- What could the group of materials P be ?
- Name the substances Q. Give two examples of such substances.
- Name the substances R. Write two examples of such substances.
- Name the substances S. Give two examples of such substances.
- Out of Q, R and S, which substances are malleable and ductile ?
State whether the following statement is true or false :
Bread is an example of solid foam.
What difference in the property of two miscible liquids enables their separation by fractional distillation ?
Name the process you would use to separate a mixture of water and alcohol.
Fill in the following blanks with suitable words :
Miscible liquids are separated by .....................
Fill in the following blanks with suitable words :
A mixture of kerosene and petrol can be separated by .....................
Fill in the following blanks with suitable words :
The gases of air can be separated by fractional distillation of liquid air because they have different..............
Fill in the following blanks with suitable words :
If a mixture contains iron filings as one of the constituents, it can be separated by using a .......................
Tincture of iodine is a mixture of two materials X and Y. The material Y has a property that its solid form can be converted directly into vapours on heating by a process called Z.
- What could X be ?
- What could Y be ?
- Name the process Z.
- Which process would you use to recover both the components X and Y from tincture of iodine ?
- Which process can be used to recover only component Y from tincture of iodine ?
What type of matter glass is?
Complete the following table:
| S.No. | CELSIUS | KELVIN |
| 1. | 90°C | 363 K |
| 2. | ______ | 283 K |
| 3. | 63 °C | ______ |
| 4. | 250°C | ______ |
| 5. | ______ | 303 K |
Higher the temperature, the higher the kinetic energy of particles.
Define the term matter.
