Answer:
The oxidation state of N in the KNO3 is +5
Explanation:
Oxidation rules:
1. Oxygen is -2, unless in peroxides.
2. Group 1 metals = +1
3. Group 2 metals = +2
4. If the molecule is neutral, all of the oxidation numbers have to add up to zero.
5. If the molecule is charged, all of the oxidation numbers have to add up to the charge of the molecule.
So, the given formula represents the salt compound formula unit of potassium nitrate: KNO3
The formula unit is uncharged.
From our rules, we know that,
O = -2
And we can find K on the periodic table, in the first group, thus giving it a +1 charge. Now let's put it all together.
K = +1
N = x
O = -2
Let's take into account the number of atoms of each element we have and make an equation since we know everything has to add up to zero since the molecules are neutral.
+1 +x+3 (-2) = 0 (notice we multiplied 3 by -2 because in the formula we have 3 atoms of oxygen with -2 charge each)
x - 5 = 0
x = 5
Therefore, the oxidation number of N in KNO3 is +5.
Answer:
volume of box is 38.81 cm³.
Explanation:
Given data:
Width of box = 4.5 cm
Height of box = 5.750 cm
Length of box = 1.50 cm
Solution:
Formula:
Volume = length × height × width
by putting values,
V = 1.50 cm × 5.750 cm× 4.5 cm
V = 38.81 cm³
Thus, the volume of box is 38.81 cm³.
Answer:
A = 0.023 m
Explanation:
The relation between the frequency of a radiation and its wavelength is given by the following expression.
where,
c is the speed of light (it has a constant value of 3.00 x 108 m/s)
A is the wavelength of the radiation v is the frequency of the radiation
In this case, the frequency is 13 GHz = 13 x
10° Hz = 13 x 1o° s-
The wavelength associated with this frequency is:
A = c/v = (3.00 x 10° m/s)/(13 x 10° s-") = 0.023
Answer:
Explanation:
Solubility of many solid in a solvent increases with increase in temperature. Increase in temperature increases kinetic energy of the solute, increasing collision and weakens the intermolecular force within the solute. This makes the solute dissolve faster in their solvents.
During recrystallization, more solutes are added to the solvent at higher temperature so that a supersaturated solution is produced on cooling. As the solution cools the over saturated solute begins to precipitate out of the solution.
Recrystallization is a form of purification if solid, as the crystalline solids continue to precipitate it reject impurities are comes out as a purer solid
