A uniform field of 2.0 N C^ -1 exists in space in the x -direction....

The electric field is given as $\vec{E} = 2.0 \hat{i} \text{ N C}^{-1}$.

The potential difference between the origin and infinity is given by the relation:

$V(0) - V(\infty) = -\int_{\infty}^{0} \vec{E} \cdot d\vec{r}$

Given $V(\infty) = 0$, we have:

$V(0) - 0 = -\int_{\infty}^{0} 2.0 dx$

$V(0) = \int_{0}^{\infty} 2.0 dx = [2.0 x]_{0}^{\infty} = \infty$

Since the calculated potential at the origin is infinite, choosing the potential at infinity to be zero is not practical for a uniform electric field.