28. If the total pressure of a mixture of four gases (neon, carbon dioxide, oxygen and hydrogen) is 1245 mm Hg, what is the pressure of neon gas if the pressure of carbon dioxide is 145 mm Hg, the pressure of hydrogen is
499 mm Hg and the pressure of oxygen is 228 mm Hg?

Partial pressure of Neon is 373 mmHg

Explanation:

In a mixture of gases, the total pressure is equal to the sum of the partial pressures of each gas. In the problem:

Total Pressure = Partial Pressure Ne + Partial Pressure CO2 + Partial pressure O2 + Partial pressure H2

Replacing:

1245 mmHg = Partial pressure Ne + 145mmHg + 228mmHg + 499mmHg

Partial pressure Ne = 1245 - 145 - 228 - 499

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.