Tag: properties of substances

Questions Related to properties of substances

The density of water is equal to :

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

  1. $10^{-3}$ $kgm^{-3}$

  2. $10^{-2}$ $kgm^{-3}$

  3. $10^{2}$ $kgm^{-3}$

  4. $10^{3}$ $kgm^{-3}$

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Correct Option: D
Explanation:

density of water in S.I. unit= ${10}^3$ kg/${m}^3$

Brine has a density of 1.2 g/cc. 40 cc of it is mixed with 30 cc of water. The density of the resulting solution will be

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

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Correct Option: B
Explanation:

Density of Brine$=\rho _{b}=1.2g/cc$

Volume of Brine$=v _{b}=40cc$
Mass of Brine$=m _{b}=\rho _{b}\times v _{b}=1.2\times 40=48g$
Density of Water$=\rho _{w}=1g/cc$
Volume of Water$=v _{w}=30cc$

Mass of Water$=m _{w}=\rho _{w}\times v _{w}=1\times 30=30g$
Density of mixture$=\dfrac{\text{Mass of mixture}}{\text{ Volume of mixture}}=\dfrac{m _{b}+m _{w}}{v _{b}+v _{w}}=\dfrac{48+30}{40+30}=\dfrac{78}{70}=1.11g/cc$

Calculate the mass of air enclosed in a room of length, breadth and height equal to $5\ m, 3 \ m$ and $4 \ m$ respectively. Density of air is $1.3 \ kg/m^3$.

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

  1. $78 \ kg$

  2. $38 \ kg$

  3. $42 \  kg$

  4. $87 \ kg$

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Correct Option: A
Explanation:

The Volume of the room is given as $V = L\times B\times H= 5\times 3\times 4 = 60  { m }^{ 3 }.$
We know, Mass $=$ Density$\times$Volume.
Given that the density $=1.3  kg/m^3$.
So, Mass of the air $=1.3\times60  Kg$.
Hence, mass of the air enclosed in the room is 78 kg.

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. $55 cc$

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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

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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

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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. ${800 kg/ m ^3}$

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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. $10^{-3}:1$

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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

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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

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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