If one chamber has a ${\psi }_w$of - 2000 KPa, and the other - 1000 K Pa, which chamber has the higher $\psi$?

Step 1. Given data:

Water potential $\left({\Psi }_w\right)$ of chamber A = $-2000KPa$

Water potential $\left({\Psi }_w\right)$ of chamber B = $-1000KPa$

Step 2. Explanation:

1. It is evident that water potential $\left({\Psi }_w\right)$ of chamber B ($-1000KPa$) has a higher water potential than the other which has water potential $\left({\Psi }_w\right)$ of $-2000KPa$.
2. ${\Psi }_w$ is always negative but its maximum value may be zero. Pure water possesses this value at atmospheric pressure.
3. Water with impurities in it has negative water potential value.
4. Water potential $\left({\Psi }_w\right)$is the measure of how easily water molecules can move in the system.

Hence, second chamber with ${\Psi }_w=-1000KPa$ has higher water potential $\left({\Psi }_w\right)$.