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# Test: Matter In Our Surroundings (Hard)

## 20 Questions MCQ Test Science Class 9 | Test: Matter In Our Surroundings (Hard)

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This mock test of Test: Matter In Our Surroundings (Hard) for Class 9 helps you for every Class 9 entrance exam. This contains 20 Multiple Choice Questions for Class 9 Test: Matter In Our Surroundings (Hard) (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Matter In Our Surroundings (Hard) quiz give you a good mix of easy questions and tough questions. Class 9 students definitely take this Test: Matter In Our Surroundings (Hard) exercise for a better result in the exam. You can find other Test: Matter In Our Surroundings (Hard) extra questions, long questions & short questions for Class 9 on EduRev as well by searching above.
QUESTION: 1

### Which of the following decreases the rate of evaporation?

Solution: When temperature and wind speed are constant, but humidity increases, the rate of evaporation will decrease.When wind speed and humidity stay constant, and temperature increases, the evaporation rate will increase because warmer air can hold more water vapour than colder air.

QUESTION: 2

### The Rate Of Evaporation Does Not Depend

Solution: The evaporation rate does not depend on the type of particles because it completely depends upon the liquid's surface area if the surface area is large, evaporation will be maximum. Evaporation depends upon wind speed; if the wind is flowing at higher speed, then the evaporation rate increases. Same will be applied in case Of Humidity. Humidity Decreases Evaporation.

QUESTION: 3

### Evaporation Is a ________phenomenon.

Solution:
QUESTION: 4

Change Of A Liquid Into Vapors at any temperature below its boiling point is called as ______________.

Solution: In the case of liquids, as mall fraction of particles at the surface, having higher kinetic energy, can break away from the forces of attraction of other particles and gets converted into vapour.This phenomenon of change of a liquid into vapours at any temperature below its boiling point is called evaporation.

QUESTION: 5

A strip of magnesium metal is burnt in the flame. It is observed that :

Solution:

It burns with a bright dazzling flame and produces magnesium oxide after burning.

QUESTION: 6

For determining the melting point of ice, the thermometer should be kept :

Solution: The bulb of the thermometer should be kept surrounded by ice cubes. Note temperature by keeping your eyes in line with the level of mercury.

QUESTION: 7

A student takes some water in a beaker and heats it over a flame for determining its boiling point. He keeps on taking its temperature reading. He observes that the temperature of the water :

Solution: It is a matter that the temperature increases till the substance are in its original state.

QUESTION: 8

Which of the following matters?

Solution: Matter, material, stuff, substance refer to that of which physical objects are composed (though all these terms are also used abstractly). As distinct from mind and spirit, Matter is a broad word that applies to anything perceived, or known to be occupying space: solid matter; gaseous matter.

QUESTION: 9

Particles of matter are

Solution: Matter on Earth is in the form of solid, liquid, or gas. Solids, liquids, and gases are made of tiny particles called atoms and molecules. In a solid, the particles are very attracted to each other. They are close together and vibrate in position but don't move past one another.

QUESTION: 10

The property to flow is unique to fluids. Which one of the following statements is correct?

Solution: Gases and liquids tend to flow and therefore behave like fluids.

QUESTION: 11

On converting 25°C, 38°C and 66°C to Kelvin scale, the correct sequence of temperature will be

Solution: 273 + 25 = 298 K, 273 + 38 = 311 K, 273 + 66 = 339 K

QUESTION: 12

The boiling points of diethyl ether, acetone and n-butyl alcohol are 35°C, 56°C and 118°C respectively. Which one of the following correctly represents their boiling points in the Kelvin scale?

Solution: 273 + 35 = 308 K, 273 + 56 = 329 K, 273 + 118 = 391 K.

QUESTION: 13

In which of the following conditions, the distance between hydrogen gas molecules would increase?

(i) Increasing pressure on hydrogen contained in a closed container

(ii) Some hydrogen gas leaking out of the container

(iii) Increasing the volume of the container of hydrogen gas

(iv) Adding more hydrogen gas to the container without increasing the volume of the container

Solution: By removing either hydrogen gas from the container or increasing the container's volume, the molecules' distance increases.

QUESTION: 14

The boiling point of a gas is − 80ºC. This temperature is equivalent to

Solution: K = 273 + °C = 273 + (– 80) = 273 – 80 = 193 K

QUESTION: 15

The standard room temperature is taken as

Solution: The standard room temperature is taken as 25°C or 298 K.

QUESTION: 16

Which of the following factors does not increase the rate of evaporation?

Solution: Increase in humidity decreases the rate of evaporation.

QUESTION: 17

The boiling point of water at normal atmospheric pressure is

Solution: The boiling point of water at normal atmospheric pressure is 100°C or 373 K.

QUESTION: 18

300 K temperature may be written in the Celsius scale as

Solution: K = 273 + °C

∴ °C = K – 273 = 300 – 273 = 27°C

QUESTION: 19

The three states of matter are:

Solution: solid, liquid and gas are three phases of all matter.

QUESTION: 20

What is the correct term for the phase change from gas directly into solid?

Solution: Sublimation involves a direct change from solid to gas. Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state.