First. moles is just a label for a number of things. just like a
dozen = 12, a gross = 144, a mole = 6022 with another 20 zeros after the
2
next
moles = mass / molecular weight.
molecular weight = sum of atomic mass from the periodic table
atomic mass MnO2 = atomic mass Mn + 2 x atomic mass O
= 54.94 + 2 x 16 = 86.94 g/mole
so moles MnO2 = 98.0 grams / (86.94 g/mole) = 1.13 moles
notice that I only gave 3 digits? that because of sig figs read the link below if you don't understand....
mw C5H12 = 5 x 12 + 12 x 1 = 72 g/mole
so moles C5H12 = 12.0 g / 72.0 g/mole = 0.167 moles
mw XeF6 = 131.3+ 6 x 19.00 = 245.3
so moles XeF6 = 100 g / 245.3 g/mole = 0.4077 moles
I've also provided a link to a periodic table. if you need atomic weights click on any element and it will give you the
details.
<span>The oxygen atom accepts the proton. The oxidation number of O is -2, meaning that there are two unshared electrons in the valence shell; In the ClO- ion, one of these is shared with the Cl- ion, leaving an unshared electron on the oxygen atom, which is what the hydrogen atom shares its electron with, becoming the proton accepted by the O atom.</span>
BIOLOGICAL & CHEMICAL EVIDENCE ANALYSIS
There are many different types of evidence that can be found at a crime scene. Physical evidence can be collected at the crime scene such as a murder weapon. Chemical evidence is any residue from liquids that such as poison and drugs. Biological evidence is when hair or skin from a persons body has been transferred to a physical surface and then be collected and tested.
This evidence can be used to find out what exactly happened at the scene of the crime, the history behind the crime and who was involved and could have committed it.
Our experts test and analyse many forms of evidence, which is vital when finding out the various incidences that happened at a crime scene.
Answer:
no of moles = (mass) ÷ molar mass
you get the molar mass from the periodic table
n = 20.0g ÷ ( 149.09 g/mol )
= 0.134 mol
number of formula units = number of moles × (6.022×10^23)
= 8.07×10^22 units
number of hydrogen atoms in (NH4)3 PO3 = 12 × number of formula units
= 9.68×10^23 hydrogen atoms
Answer:
Option B
Transfers energy to the water
Explanation:
Warm air transfers energy to the water when it flows over cold currents. This means that the warm air loses heat energy to the cold currents thus, raising its temperature.
Whenever there is a temperature difference between two bodies in contact with each other, the Fouriers law explains that there is always a transfer of heat from the hotter body to the colder body until they become the same temperature.
Thus, following this, heat will flow from the warm air to the cold currents.
