I'll be using dimensional analysis to help out.
2.5mol Na2O * ( X gNa2O / 1 molNa2O) = ? gNa2O
X gNa2O is the molar mass of the molecule. To find that we must add up the molar masses of all of the elements in the molecule.
There are 2 Na (Sodium).
And 1 O (Oxygen).
The Molar Mass of Na = 2 * 22.99 g/mol (It's multiplied by 2 because there are 2 of them in the molecule)
The Molar mass of O = 16.00 g/mol
If you are confused on where I found them. Let me enlighten you! I found them from a periodic table of elements.
Add those two values together to get a total molecular molar mass of:
38.99g/mol
2.5mol Na2O * ( 38.99 gNa2O / 1 molNa2O) = 97 gNa2O
the answer is A. temperature
Kelvin is the standard measurement unit for temperature
the temperature at which the gas molecules exert the smallest pressure is the absolute zero in the Kelvin scale. At absolute zero the gas molecules have minimal motion.
Pressure is directly proportional to temperature of the kelvin scale.
0 K is equivalent to - 273.15 °C
H2O has a bent structure. The oxygen atom is in the center, and the hydrogen atoms are attached but pointing downward. It's not linear because there are two unshared pairs of electrons on oxygen that take up their own spaces.