<span>128 g/mol
Using Graham's law of effusion we have the formula:
r1/r2 = sqrt(m2/m1)
where
r1 = rate of effusion for gas 1
r2 = rate of effusion for gas 2
m1 = molar mass of gas 1
m2 = molar mass of gas 2
Since the atomic weight of oxygen is 15.999, the molar mass for O2 = 2 * 15.999 = 31.998
Now let's subsitute the known values into Graham's equation and solve for m2.
r1/r2 = sqrt(m2/m1)
2/1 = sqrt(m2/31.998)
4/1 = m2/31.998
127.992 = m2
So the molar mass of the unknown gas is 127.992 g/mol.
Rounding to 3 significant figures gives 128 g/mol</span>
B. the frogs are a limiting factor for the gnats
the frogs limit the reproduction of the gnats, and therefore with less frogs the gnat population can increase
Answer:
Displaced
Explanation:
A convenient way to measure the volume of an object is to measure the volume of a solid is to immerse the solid into water.
When a solid is immersed in water, it displaces some volume of water. This volume of water displaced is the same as the volume of the object.
For instance, if the volume of water in a measuring cylinder was 25 ml and i added a stone which made the water in the measuring cylinder to rise to 70 ml, it simply means that the volume of the object is 70 ml - 25 ml = 45 ml
