According the van der Waal's theory of non-ideal gases, which of the following statement is/are correct?

Options

A. `H_(2)` and He are impossible to liquefy at room temperature
B. For `NH_(3)`, Z decreases more rapidly on increasing pressure than the methane in lower pressure region.
C. In the low pressure region Z decrease on increasing pressure `H_(2)` and He are exception to that.
D. In the high pressure region Z increases with increasing pressure, `H_(2)` and He are exception to that.

Answer

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