Answer : The molecular weight of a gas is, 128.9 g/mole
Explanation : Given,
Density of a gas = 5.75 g/L
First we have to calculate the moles of gas.
At STP,
As, 22.4 liter volume of gas present in 1 mole of gas
So, 1 liter volume of gas present in
mole of gas
Now we have to calculate the molecular weight of a gas.
Formula used :

Now put all the given values in this formula, we get the molecular weight of a gas.


Therefore, the molecular weight of a gas is, 128.9 g/mole
<span>a. x and y are atoms of the same element.
If both atoms contain the same amount of protons, they are always the same element.
</span>
Answer: I think the answer is 1
i just learned this about two weeks ago
Explanation:
<span>0.0292 moles of sucrose are available.
First, lookup the atomic weights of all involved elements
Atomic weight Carbon = 12.0107
Atomic weight Hydrogen = 1.00794
Atomic weight Oxygen = 15.999
Now calculate the molar mass of sucrose
12 * 12.0107 + 22 * 1.00794 + 11 * 15.999 = 342.29208 g/mol
Divide the mass of sucrose by its molar mass
10.0 g / 342.29208 g/mol = 0.029214816 mol
Finally, round the result to 3 significant figures, giving
0.0292 moles</span>
The order of placement of the elemnts on the modern Periodic Table is determinated by:
1)atomic number (Z=number of protons).