A flask contains a mixture of hydrogen gas and water vapor at STP. If the pressure of the water vapor is 19.5 mmHg, then what is the pressure of the hydrogen gas? 779 mmHg
779 mmHg

760 mmHg
760 mmHg

81.7 mmHg
81.7 mmHg

741 mmHg

The table lists the lattice energies of some compounds.compoundlattice energy (kj/mol)lif            –1,036licl            –853naf            –923kf            –821nacl            –786which statement about crystal lattice energy is  best  supported by the information in the table? the lattice energy increases as cations get smaller, as shown by lif and kf.the lattice energy increases as the cations get larger, as shown by lif and licl.the lattice energy decreases as cations get smaller, as shown by nacl and naf.the lattice energy decreases as the cations get smaller, as shown by naf and kf.