Download App

PART - 1 CH - 5 Thermodynamics — Chemistry STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 ScienceChemistryPART - 1 CH - 5 Thermodynamics2 Marks
Question
Explain the free expansion of gas.
✓

Answer

The expansion of gas in vacuum is known as free expansion of gas. In free expansion of ideal gas there is no work done.
According to first law of thermodynamics :
$
\begin{array}{l}
\Delta U=q+w \\
\left(w=-p_{e x} \Delta V\right)
\end{array}
$
On putting value of w
$
\Delta U=q-p_{cx} \Delta V
$
For isochoric process : $\Delta V =0$
Hence $\quad \Delta U=q_v$
The free and isothermal expansion of an ideal gas can be done in vacuum than ( $T =$ constant), so $w=0$ because $p _{ ex }=0$. Joule do experiments and concluded if $q =0$ then $\Delta U =0$.

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 "2 Marks Questions" from PART - 1 CH - 5 Thermodynamics→PART - 1 CH - 5 Thermodynamics — all question types→Chemistry STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

Magnesium and Lithium both form nitride, why? Write the equation for formation of their nitride.
→
  1. How many subshells are associated with n = 5?
  2. Write the electronic configuration of Fe2+ ions (z = 26)
→
What is salt bridge?
→
In comparison to the atomic mass of an element, the atomic number is more capable of indicating the properties of that element. Confirm the statement.
→
Out of H and H2, the latter has higher first ionisation energy while out of 0 and O2, the former has higher first ionisation energy. Explain why?
→
Consider the following reaction:

H2(g) + F2(g) → 2HF(g)

$\Delta\text{H}^\circ=-542\text{kJ},\ \Delta\text{S}^\circ=14\text{JK}^{-1}$

Calculate the $\Delta\text{G}^\circ$ value for the reaction and state if the reaction is spontaneous at 298K.

→
  1. Define the term redox couple. Write the practical application of redox couple.
  2. Split $2\text{K}\text{(s)}+\text{Cl}_2\text{(g)}\xrightarrow{ \ \ \ \ \ }2\text{KCl}\text{(s)}$ into oxidation and reducton half reaction.
→
Depict the galvanic cell in which the reaction Zn(s) + 2Ag+(aq) → Zn2+(aq) + 2Ag(s) takes place, Further show:

The carriers of the current in the cell.

→
The first ($(\Delta_{1}\text{H}_{1})$ and the second $(\Delta_{1}\text{H}_{1})$ ionization enthalpies (in kJ mol–1) and the $(\Delta_{1}\text{H}_{1})$ electron gain enthalpy (in kJ mol–1) of a few elements are given below:
Elements $\Delta\text{H}_{1}$ $\Delta{\text{H}}_{2}$ $\Delta_{\text{eg}}\text{H}$
I 520 7300 -60
II 419 3051 -48
III 1681 3374 -328
IV 1008 1846 -295
V 2372 5251 +48
VI 738 1451 -40
Which of the above elements is likely to be:
The most reactive non-metal.
→
Justify that the following reactions are redox reactions:

2K(s) + F2(g) → 2K+F-(s)

→