Tag: chemistry

Questions Related to chemistry

If the temperature of a water bath is $104^{0}\ F$ then its value in degree Celsius scale will be?

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

  1. $35^{0}C$

  2. $45^{0}C$

  3. $50^{0}C$

  4. $40^{0}C$

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Correct Option: D
Explanation:

Conversion from Fahrenheit to Celsius



$(T\ °F − 32) \times \dfrac{5}{9} = t\ °C$

Substituting it, we get,

$(104\ °F − 32) \times \dfrac{5}{9} = 40\ °C$


Hence, the correct option is $D$

Thermometer $(A) & (B)$ have ice points marked at $15^oC & 25^oC$ and steam points at $75^oC & 125^oC$ respectively. When thermometer A measures the temperrature of a bath as $60^oC$ the reading of B for the same bath 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. $60^oC$

  2. $75^oC$

  3. $90^oC$

  4. $100^oC$

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Correct Option: B

Weight of a body 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. constant

  2. not constant

  3. does not change from place to place

  4. both A and C

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Correct Option: B
Explanation:

Mass of a body is constant whereas weight of a body depends on the acceleration due to gravity at that point. Therefore, weight of body is not constant & varies from place to place.

Parsec is the unit 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. Speed

  2. Time

  3. Distance

  4. None of the above

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Correct Option: A,C

Electron Volt is a unit 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. Potential difference

  2. Energy

  3. Charge

  4. Velocity

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Correct Option: B
Explanation:

The electron volt (symbol eV; also written electronvolt) is a unit of energy equal to approximately 1.602$\times$10$^{−19}$ joule (SI unit J). 


By definition, it is the amount of energy gained by the charge of a single electron moved across an electric potential difference of one volt.

Hence, the correct option is $B$

The international standards of weight and measures are made 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. gold silver alloys

  2. platinum - iridium alloys

  3. copper - gold alloys

  4. platinum - iron alloys

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Correct Option: B
Explanation:
The addition of 10% iridium to the platinum greatly increases its hardness and so reduces wear.Hence the international standards of weight and measures are made up of platinum and iridium alloys.

On Celsius scale, $0$ Kelvin 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. $273^0C$

  2. $0^oC$

  3. $-273^oC$

  4. $-373^oC$

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Correct Option: C
Explanation:

To convert from Kelvin scale to Celsius scale, subtract 273 from Celsius scale. 

$0K=$$0-273=-273^oC$

What is the physical state of water at $-20^{\circ}C$?

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

  1. Solid

  2. Liquid

  3. Gas

  4. None of the above

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Correct Option: A
Explanation:

Water at $-20^{\circ}C$ is ice so it is in solid state. It freezes at $0^{\circ}C$.

Convert 44 K into Celsius scale.

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

  1. $-233^oC$

  2. $-229^oC$

  3. $-212^oC$

  4. $-239^oC$

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Correct Option: B
Explanation:

To convert from Kelvin scale to Celsius scale, subtract 273 from Kelvin scale, so $44-273=-229^oC$.


Hence, option $B$ is correct.

The centigrade $(^0 C)$ scale can be converted into Kelvin scale by the formula:

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

  1. Temperature in Kelvin + 273

  2. Temperature in Kelvin - 273

  3. Temperature in Fahrenheit + 273

  4. Temperature in Fahrenheit - 273

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Correct Option: B
Explanation:

The temperature T in Kelvin (K) is equal to the temperature T in degrees Celsius $\displaystyle \left( ^{ \circ  }{ C } \right) + 273$: 


$\displaystyle { T } _{ \left( k \right)  }={ T } _{ \left( ^{ \circ  }{ C } \right)  }+273.15$

Therefore, temperature in $\displaystyle ^{ \circ  }{ C }$ =  temperature in Kelvin +273.

Hence, option B is correct.