You are given that mass of _3^7 L=7.0160 u, Mass of _2^4 He =4.00…

MCQ

You are given that mass of ${ }_3^7 L=7.0160 u$,
Mass of ${ }_2^4 He =4.0026 u$
and Mass of ${ }_1^1 H =1.0079 u$
When 20 g of ${ }_3^7 Li$ is converted into ${ }_2^4 He$ by proton capture, the energy liberated, (in kWh ), is:
[Mass of nucleon $=1 GeV / c ^2$ ]

A
$4.5 \times 10^5$
B
$8 \times 10^6$
C
$1.33 \times 10^6$
D
$6.82 \times 10^5$

✓

Answer

C. $1.33 \times 10^6$
Explanation:
$\begin{array}{l}{ }_3^7 Li +{ }_1^1 H \longrightarrow 2\left({ }_2^4 He \right) \\ \Delta m \rightarrow\left[ m _{ Li }+ m _{ H }\right]-2\left[ M _{ He }\right] \\ \text { Energy released }=\Delta mc ^2 \\ \text { In use of } 1 g Li \text { energy released }=\frac{\Delta m c^2}{m_{ Li }} \\ \text { In use of } 20 g \text { energy released }=\frac{\Delta m c^2}{m Li} \times 20 g \\ =\frac{[(7.016+1.0079)-2 \times 4.0026] u \times c^2}{7.016 \times 1.6 \times 10^{-24}} \times 20 g \\ =\left(\frac{0.0187 \times 1.6 \times 10^{-19} \times 10^9}{7.016 \times 1.6 \times 10^{-24}} \times 20\right)=480 \times 10^{10} J \\ \because 1 J=2.778 \times 10^{-7} kWh \\ \therefore \text { Energy released }=480 \times 10^{10} \times 2.778 \times 10^{-7} \\ =1.33 \times 10^6 kWh \end{array}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "SECTION - A [PHYSICS - MCQ]" from Model Paper 9→Model Paper 9 — all question types→NEET STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

The displacement of a particle executing simple harmonic motion is given by

$\mathrm{y}=\mathrm{A}_{0}+\mathrm{A} \sin \omega \mathrm{t}+\mathrm{B} \cos \omega \mathrm{t}$

Then the amplitude of its oscillation is given by

→

Potential energy as a function of $r$ is given by $U=\frac{ A }{ r ^{10}}-\frac{ B }{ r ^{5}}$, where $r$ is the interatomic distance, $A $ and $B$ are positive constants. The equilibrium distance between the two atoms will be

→

A current source drives a current in a coil of resistance $R_1$ for a time $t$. The same source drives current in another coil of resistance $R_2$ for same time. If heat generated is same, find internal resistance of source.

→

Consider the reactions, Identify $A, \,X,\, Y$ and $Z.$

$\underset{({{C}_{2}}{{H}_{6}}O)}{\mathop{X}}\,\,\xrightarrow[573\,\,K]{Cu}$ $A$ $\xrightarrow[^{-}OH\,,\,\Delta ]{{{[Ag{{(N{{H}_{3}})}_{2}}]}^{+}}}$ Silver mirror

$A\,\xrightarrow{^{-}OH\,,\,\Delta }Y$

$A\,\xrightarrow{N{{H}_{2}}NHCON{{H}_{2}}}Z$

→

Assertion : Environmental damage has increased the amount of ozone in the atmosphere.

Reason : Increase of ozone increases the amount of ultraviolet radiation on earth.

→

In the above thermodynamic process, the correct statement is