Answer:
It ability to react with oxygen.
Explanation:
Freezing point and hardness can be altered. Physical properties can also be reversed. Chemical properties on the other hand cannot. The product after reaction with an element never changes.
Answer:
(A) is 0.0773 mol B2H6
(C) is 2.79 x 10^23 H atoms
Explanation:
Questions (A) and (B) are the same.
2.14 g B2H6 x (1 mol B2H6/27.668g B2H6) = 0.0773 mol B2H6 (A)
<u>27.668 is the molar mass of B2H6 calculated from the period table: </u>
(2 x 10.81) + (6 x 1.008) = 27.668
1.008 is the mass of H and 10.81 is the mass of B
(C)
0.0773 mol B2H6 x (6 mol H/ 1 mol B2H6) x (6.022 x 10^23 H atoms/1 mol H)
= 2.79 x 10^23 hydrogen atoms
Further Explanation:
- For every 1 mol of B2H6, there are 6 moles of H (indicated by the subscript)
- 6.022 x 10^23 is Avogrado's number and it equals to 1 mol of anything
- Avogrado's number can be in units of atoms, molecules, or particles
Using dimensional analysis, we can find the moles of strontium by comparing the mass of strontium to it's atomic mass.
You can find the atomic mass of Sr on the periodic table:
Atomic Mass Sr = 87.62g/mol
In case you are not familiar, dimensional analysis works like this:
(what we know) x (conversion factor) = what we are looking for
The conversion factor compares the units of what we know to the units of what we are looking for. In this case, the conversion factor is:
1 mol/87.62g
The important thing to note about the conversion factor is that you want to be able to cancel out the units of your given measurement (in this case, it is the mass)
So, our full solution will be:
moles Sr = (175.24 g)x(1 mol/87.62 g)
(cancel out the mass units)
moles Sr = 175.24 x 1 mol/87.62
= 2.00 mol Sr
Hope this helped you!
If it gains an electron it will be negatively charged and if it loses an electron it will be positively charged
