Answer:
They are averages.
Explanation:
atomic numbers on periodic tables are derived from the average value of all the isotopes of the element. So being averages they are sometimes not integers.
Answer:
<em>(H30+)= 1x10^-6 M</em>
Explanation:
Both pH and pOH have a relationship to belonging to the same aqueous solution: the expression of the Kwater (ionic product of the water Kw) is used:
1x 10-8 mol/L equals to1x10-8 M
(H3O+) x (OH-) = 1x10^-14
(H30+)x 1x 10^-8 =1x10^-14
(H30+)= 1x10^-14/1x 10^-8
<em>(H30+)= 1x10^-6 M</em>
Answer:

Explanation:
Given that,
The distance between the centers of the two oxygen atoms in an oxygen molecule is
.
We need to convert this distance in inches.
We know that,
1 cm = 0.393 inches
We can solve it as follows :

So, the distance between the centers of the two oxygen atoms is
.
Answer:
Number of moles = 2.8 mol
Explanation:
Given data:
Number of moles of water = ?
Volume of water = 50 mL
Density of water = 1.00 g/cm³
Solution:
1 cm³ = 1 mL
Density = mass/ volume
1.00 g/mL = mass/ 50 mL
Mass = 1.00 g/mL× 50 mL
Mass = 50 g
Number of moles of water:
Number of moles = mass/molar mass
Number of moles = 50 g / 18 g/mol
Number of moles = 2.8 mol
Answer:
-514 kJ/mol
Explanation:
The bond enthalpy which is also known as bond energy can be defined as the amount of energy needed to split one mole of the stated bond. The change in enthalpy of a given reaction can be estimated by subtracting the sum of the bond energies of the reactants from the sum of the bond energies of the products.
For the given chemical reaction, the change in enthalpy of the reaction is:
Δ
[2(409) + 4(388) + 3(496) - 4(630) - 4(463)] kJ/mol = 818 + 1552 + 1488 - 2520 - 1852 = -514 kJ/mol