Answer:
13.7 moles
Explanation:
Given data:
Number of moles calcium carbonate = ?
Formula units calcium carbonate= 8.23 × 10²⁴
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For 8.23 × 10²⁴ formula units:
one mole = 6.022 × 10²³ formula units
8.23 × 10²⁴ formula units × 1 mole /6.022 × 10²³ formula units
13.7 moles
It's only a small difference (103 degrees versus 104 degrees in water),
and I believe the usual rationalization is that since F is more
electronegative than H, the electrons in the O-F bond spend more time
away from the O (and close to the F) than the electrons in the O-H bond.
That shifts the effective center of the repulsive force between the
bonding pairs away from the O, and hence away from each other. So the
repulsion between the bonding pairs is slightly less, while the
repulsion between the lone pairs on the O is the same -- the result is
the angle between the bonds is a little less.
Hope this helps!
Balance
Usually it’s a triple beam balance.
A ruler measures length
<span>c = speed of light = 3.00 x 10^5 km/s = 3.00 x 10^8 m/s
λ = wavelength of the microwave radiation = 3.50 cm = 0.035 m
f = frequency (in Hertz) = to be determined
f = c/λ = 3.00 x 10^8 m/s / 0.035 m
f = 8.57 x 10^9 Hz Frequency</span>
Atoms are the basic units of matter and the defining structure of elements. We count the number of atoms by the total number of elements present in the compound. In this case, we have 1 atom of Si and 2 atoms of oxygen which would have 3 total number of atoms.
