Tag: substances in the surroundings - their states and properties

Questions Related to substances in the surroundings - their states and properties

If the mass of a body is 12.1 g and the density is 2.2g/cc, its volume is :

chemistry substances in the surroundings - their states and properties measurement of density properties of substances fundamental and derived units

  1. $\displaystyle 5.5{ cm }^{ 3 }$

  2. $8 cc$

  3. $11 cc$

  4. $55 cc$

Show answer
Correct Option: A
Explanation:
density $\rho=\dfrac{mass}{ volume}$

$2.2=\dfrac{12.1}{volume}$

volume $=5.5{cm}^3$

The SI unit of density is $\displaystyle kg\ { m }^{ -3 }$. State whether true or false.

chemistry substances in the surroundings - their states and properties measurement of density properties of substances fundamental and derived units

  1. True

  2. False

Show answer
Correct Option: A
Explanation:
S.I unit of density is kg/${m}^3$
since, density=mass/volume

If two masses A and B have their masses in the ratio 1 : 4 and their volumes are equal, then their densities have the ratio

chemistry substances in the surroundings - their states and properties measurement of density properties of substances fundamental and derived units

  1. 1:4

  2. 8:1

  3. 2: 4

  4. 3:1

Show answer
Correct Option: A
Explanation:

Let mass of $A$ be $m$

Mass of $B$ be $4m$
Let density of $A$ be $d _a$
Density of $B$ be $d _b$
And Volume of A$=$Volume of B$=V$
As Density$=\dfrac{\text {Mass}}{\text {Volume}}$

Therefore $d _a=\dfrac{m}{V}$
$d _b=\dfrac{4m}{V}$

$\dfrac{d _a}{d _b}=\dfrac{\dfrac{m}{V}}{\dfrac{4m}{V}}$
$\dfrac{d _a}{d _b}=\dfrac{m}{4m}=\dfrac{1}{4}$
Hence the correct answer is option (A).

What is the density of an iron block which has a volume of ${12 cm^3}$ and a mass of 96g?

chemistry substances in the surroundings - their states and properties measurement of density properties of substances fundamental and derived units

  1. ${ 8 kg/m ^3}$

  2. ${80 kg /m ^3}$

  3. ${8000 kg /m ^3}$

  4. ${800 kg/ m ^3}$

Show answer
Correct Option: A
Explanation:

Answer is A.

As we know, Density $d = \dfrac{Mass, M}{ Volume, V}$


In this case, an iron block which has a volume of ${12 cm^3}$ = ${0.12 m^3}$ and a mass of $96 g = 0.096 kg$.

Therefore, Density $d =\dfrac{ 0.096}{0.12} = 8 kg/m^{ 3 }$.

Hence, the density of the iron block is 8 $kg/m^{ 3 }$.

The ratio of the values in SI units to values in CGS units of density is

chemistry substances in the surroundings - their states and properties measurement of density properties of substances fundamental and derived units

  1. $10^3:1$

  2. $10^2:1$

  3. $10^{-2}:1$

  4. $10^{-3}:1$

Show answer
Correct Option: A
Explanation:

the density of water in S.I. unit $\rho=1000 kg/{m}^3$

the density of water in CGS unit $\rho'=1 gm/cc$

the ratio of the densities of water in the different system 
$\dfrac{\rho}{\rho'}=\dfrac{{10}^3}{1}$

The density of water is $\displaystyle { 10 }^{ 3 }kg\ { m }^{ -3 }$. State whether true or false.

chemistry substances in the surroundings - their states and properties measurement of density properties of substances fundamental and derived units

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

It is a fact that the density of water is 1000 kg / ${m}^3$

When air is cooled, its density increases. State whether true or false.

chemistry substances in the surroundings - their states and properties measurement of density properties of substances fundamental and derived units

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

 As on cooling volume of air decreases and its mass remains constant so its density increases as  Density = $\dfrac{mass}{volume}$

hence given statement is correct so option (A) is correct

The hot air balloon rises because it is

chemistry substances in the surroundings - their states and properties measurement of density properties of substances fundamental and derived units

  1. denser

  2. less dense

  3. equally dense

  4. the given statement is wrong

Show answer
Correct Option: B
Explanation:

The hot air balloon has the hot air filled in it and the density of air is more than the hot air. So, the normal air or atmospheric air has the tendency to remain below than the hot air as the objects having the more density remains below than the objects having less density.

Brine has a density of $1.2  {g}/{cc}$. $40  cc$ of it are mixed with $30  cc$ of water. The density of solution is

chemistry substances in the surroundings - their states and properties measurement of density properties of substances fundamental and derived units

  1. $2.11 {g}/{cc}$

  2. $1.11 {g}/{cc}$

  3. $12.2 {g}/{cc}$

  4. $20.4 {g}/{cc}$

Show answer
Correct Option: B
Explanation:
given,  ${ \rho } _{ a }=1.2\quad 9/cc\quad \quad \quad { V } _{ a }=40cc$
                 ${ \rho } _{ b }=1g/cc\quad \quad \quad { V } _{ b }=30cc$

$ \rho _{mixture} = \dfrac { { \rho } _{ a }{ V } _{ a }+{ \rho } _{ b }{ V } _{ b } }{ { V } _{ a }+{ V } _{ b } } $

So  $ \rho _{mixture} = \dfrac { 1.2\times 40+1\times 30 }{ 40+30 } =\dfrac { 78 }{ 70 } $

        $\boxed { \rho _{mixture}=1.11\quad g/cc } $

With the increase in temperature, the density of a substance, in general, ____________.

chemistry substances in the surroundings - their states and properties measurement of density properties of substances fundamental and derived units

  1. increases

  2. decreases

  3. first increase then decreases

  4. first decrease then increases

Show answer
Correct Option: B
Explanation:

Due to increase in temperature, objects vibrational energy increases resulting in decrease in density of the substance.