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Structure Of Atom

Question
CBSEENCH11005233
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Find: (a) the total number and (b) the total mass of protons in 34 mg of NH3 at STP.
Will the answer change if the temperature and pressure are changed ?

Solution

(a) 1 molecule of NH3 contains
                           = 7 + 3 = 10 protons
therefore space space space 6.022 space cross times space 10 to the power of 23 space molecules space of space NH subscript 3 space would space contain space space space space space space space space space space space space space equals space 10 space cross times space 6.022 space cross times space 10 to the power of 23 space protons
                               equals space 6.022 space cross times space 10 to the power of 24 space protons
Now  17g NH3 contains 6.022 x 1024 protons
therefore space space 34 space mg space straight i. straight e. space 0.034 space straight g space NH subscript 3 space would space contain space equals space fraction numerator 6.022 space cross times space 10 to the power of 24 over denominator 17 end fraction cross times 0.034 space space equals space 1.2044 space cross times space 10 to the power of 22 space protons

(b) Mass of one proton = 1.6726 x 10-27 kg
therefore space space Mass space of space 1.2044 space cross times space 10 to the power of 22 space protons space space space space space space space equals left parenthesis 1.6726 space cross times space 10 to the power of negative 27 end exponent kg right parenthesis space left parenthesis 1.2044 space cross times space 10 to the power of 22 right parenthesis space space space space space space space equals space 2.0145 space cross times space 10 to the power of negative 5 end exponent kg
There is no effect of temperature and pressure.

Some More Questions From Structure of Atom Chapter

Who discovered neutron?

What is a neutron?

What is the name of the remaining part of atom except outer orbit?

Name the particles which determine the mass of an element.

What are α-particles?

Why were neutrons discovered very late?

What are the fundamental particles present in a neutral atom having atomic number greater than 1?

Do protons and neutrons have identical mass?

When α-particles are sent through a thin metal foil, most of them go straight through the foil. What inference do you draw from it?

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