Independent and dependent variables and constants
Answer:
Explanation:
Method 1 proportion
1 mole of chromium is 52 grams
11.9 moles = x grams
1/11.9 = 52/x Cross multiply
x = 11.9 * 52
x = 618.8 grams
Now I have used an approximate mass for Chromium. The answer you get here is expected to reflect the weigth given on your periodic table Use that to get your answer. You should give a number very close to mine. Round to 3 places as in 619.
Method Two Formula
mols = given mass / molecular mass
11.9 = given mass / 51.9961 Multiply both sides by 51.9961
11.9 *51.9961 = given mass
given mass = 618.75
given mass = 619
Answer: Total pressure inside of a vessel is 0.908 atm
Explanation:
According to Dalton's law, the total pressure is the sum of individual partial pressures. exerted by each gas alone.

= partial pressure of nitrogen = 0.256 atm
= partial pressure of helium = 203 mm Hg = 0.267 atm (760mmHg=1atm)
= partial pressure of hydrogen =39.0 kPa = 0.385 atm (1kPa=0.00987 atm)
Thus 
=0.256atm+0.267atm+0.385atm =0.908atm
Thus total pressure (in atm) inside of a vessel is 0.908