g A mixture of gasses comprised of oxygen, nitrogen, and hydrogen has a total pressure of 760 mm Hg. The pressure due to hydrogen was found to be 70 mm Hg and the pressure due to oxygen was 650 mm Hg. What was the partial pressure of nitrogen

40 mmHg

Explanation:

Dalton's Law of Partial Pressures, states that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the individual gases in the mixture. Hence if I have gases A,B and C and I choose to designate the pressure of gas A as PA, the pressure of gas B as PB , the pressure of gas C as PC and the total pressure of all the gases together as PT. Then from Dalton's law; PT= PA + PB + PC

From the question; we designate the pressure of hydrogen as PA, pressure of nitrogen as PB and pressure of oxygen as PC.

PA= 70 mmHg

PB= the unknown

PC= 650 mmHg

If the total pressure of the gas mixture (PT) = 760 mmHg

Then;

760= 70 + PB + 650

PB= 760- (70+650)

PB= 760 - 720

PB= 40 mmHg

Therefore, the partial pressure of nitrogen is 40 mmHg

its first and third is your answer i did the qustion the fourth isnt right

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72