From what you know about helium and the elements in its group, which statement best explains why helium is placed where it is, i
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Answer:- molar mass of the unknown gas is 71.5 gram per mol.
Solution:- From Graham's law of effusion rates, the rate of effusion of a gas is inversely proportional to the square root of it's molar mass.
When we compare the effusion rates of two gases then the formula for Graham's law is:
In this formula, V stands for volume and M stands for molar mass
Rate is volume effused per unit time. Since, the volumes are same, the formula could be written as:
let's say in formula, subscript 1 is for hydrogen gas and 2 is for the unknown gas.
Molar mass of hydrogen is 2.02 grams per mol and the time taken to effuse it is 2.42 min. The time taken to effuse the unknown gas is 14.4 min and we are asked to calculate it's molar mass. let's plug in the values in the formula:
doing squares to both sides:
So, the molar mass of the unknown gas is 71.5 grams per mol.
Aluminum ions have a charge of +3. This means that the atoms have three more protons than electrons. In order to add electrons to aluminum ions, the purification process therefore requires a large amount of electricity.
Uncharged Aluminum atom must need to lose it's electrons,in order to form the bond with oxygen which has vacant orbitals
ion
atom that has a positive or negative charge because it lost or gained one or more electrons
chemical bond
the attractive force that holds atoms or ions together
ionic bond
a chemical bond in which one atom loses an electron and the other atom gains electrons to form ions
chemical formula
a combination of chemical symbols and numbers to represent a substance
covalent bond
bond formed by the sharing of electrons between atoms
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