Question

In the reaction $H_{2}O\left(l\right)\to H_{2}O\left(s\right)$, at constant pressure, the work done by system on surrounding is:

• A. negative
• B. positive
• C. zero
• D. none of these

Answer 1

The correct option is A negative

At constant pressure,

$dW=-PdV$

$H_2\left(l\right)\to H_{2}O\left(s\right)$

$V_{\left(l\right)}<V_{\left(s\right)}$

Hence, $W=-ve$ since the volume expands.