Tag: chemistry

Questions Related to chemistry

Which of the following is the non- derived unit?

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. Time

  2. Mass

  3. Length

  4. All of the above

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Correct Option: D
Explanation:

Non-derived units or fundamental units are the units which are used to derive other units. The fundamental units are length, mass, temperature, time, electric current, liminous & mole.

Which of the following is not a basic physical quantity?

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. Length

  2. Time

  3. Density

  4. Amount of substance

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Correct Option: C
Explanation:

Basic physical quantities are those that are physical fundamental units. There are seven basic fundamental quantities: Length, mass, time, electric current, amount of substance, luminous intensity & temperature. The quantities which are derived with the help of these basic physical quantities are called derived quantities. They are density, volume, pressure, force, etc.

What should be the volume of the milk (in $m^3$) which measures 5 L?

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. $5 \times 10^{-3} m^{3}$

  2. $5 \times 10^{3} m^{3}$

  3. $5 \times 1000 \ m^{3}$

  4. $5 \times 10^{6} m^{3}$

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Correct Option: A
Explanation:
$1\ L=10^{-3}\ m^{3}$
Since 1 L = 1000 $cm^3$ and 1 m = 100 cm
$\dfrac {1 m}{100 cm} = 1 = \dfrac{100 cm}{1 m}, or (\dfrac {1 m}{100 cm})^3 = \dfrac{1m^3}{10^6cm^3}$ = $1^3$ = 1

Therefore $5\ L=5 \times 10^{-3}\ m^{3}$
option A is correct

The least count of burette used normally is $x$ (in mL). The value of $10x$ is:

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. 1

  2. 1.5

  3. 0.10

  4. none of these

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Correct Option: A
Explanation:

Normally least count of burette is $ 0.10 cm^3$.

So value of $10 x=10\times0.10=1$

How many seconds are there in 3 days?

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. 259200 s

  2. 172800 s

  3. 24800 s

  4. 72000 s

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Correct Option: A
Explanation:

$1\ min=60\ s$

$1 h = 60 min = 60 \times 60 s=3600\ s$
$1 day =24\ h=24 \times 3600\ s=86400\ s$
$3 days =3 \times 86400\ s=259200\ s$
option A is correct

Value of Plank's constant is equal to:

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. $6.625 \times 10^{-34}$ J. sec.

  2. $6.25 \times 10^{-34}$ J. sec.

  3. $662.5 \times 10^{-34}$ J. sec.

  4. none of these

Show answer
Correct Option: A
Explanation:

The Planck's constant is named after the physicist Max Planck. It links the frequency of the electromagnetic wave of a photon to its amount of energy.

         $E=hv$
$h\rightarrow$ planck's constant $=6.625\times 10^{-34} J.sec.$

Temperature is a measure of :

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. the average kinetic energy of the particles in a substance.

  2. the average potential energy of the particles in a substance.

  3. the highest amount of kinetic energy the particles in a substance have.

  4. the number of particles a substance has.

  5. the amount of heat a substance has.  

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Correct Option: A,E
Explanation:

Temperature is a measure of the average kinetic energy of the particles in a substance. 


As the average kinetic energy of the particles in a gas is proportional to the temperature of the gas.

Hence the correct options are A and E.

Which units of pressure are needed if you are going to use 0.0821 as your ideal gas constant?

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. Atmospheric

  2. Torr

  3. Psi

  4. mmHg

  5. Pascals

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Correct Option: A
Explanation:

Gas constant = $0.0821 $  $L atm K^{−1} mol^{−1}$


atm ( Atmospheric unit is used )

Hence the correct option is A.

Which of the following measures pressure?

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. Barometer

  2. Thermometer

  3. Pycnometer

  4. Parameter

  5. Pressometer

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Correct Option: A
Explanation:

A barometer is a scientific instrument used in meteorology to measure atmospheric pressure. Pressure tendency can forecast short term changes in the weather. Numerous measurements of air pressure are used within surface weather analysis to help find surface troughs, high pressure systems and frontal boundaries.

Ammonia is used in detection of $Cu^{2+}$ ion because:

chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

  1. aqueous solution of $NH _{3}$ reacts with $Cu^{2+}$ ion to form deep blue coloured complex

  2. $NH _{3}$ reacts with $Cu^{2+}$ ion to give blue precipitate of $CuO$

  3. aqueous solution of $NH _{3}$ reacts with $Cu^{2+}$ ion to form white coloured complex.

  4. $NH _{3}$ reacts with $Cu^{2+}$ ion to give green precipitate.

Show answer
Correct Option: A
Explanation:

Ammonia acts as a Lewis base due to the presence of lone pair of  on the nitrogen atom.so,it can form coordinate bond transition metal cations to from complex compounds.Ammonia reacts with a solution of $Cu^{2+}$  to from a deep blue coloured complex.The reaction for the above complex  compound can be written as follows:

$Cu^{2+}(aq) + 4 NH _3(aq)\rightarrow [Cu(NH _3) _4]^{2+}(aq)$

                                                                              Deep Blue

Hence option A is correct.