The answer to this question would be: alkaline earth metal
Alkali earth metal is the second column group of the periodic table. In this group, the element has 2 extra electrons in their outer cells. That is why most of this metal has 2+ charge.
Their neighbor is the alkali metal which was the first column of the periodic table. The name is similar so don't confused and mix them each other.
Ok first, we have to create a balanced equation for the dissolution of nitrous acid.
HNO2 <-> H(+) + NO2(-)
Next, create an ICE table
HNO2 <--> H+ NO2-
[]i 0.230M 0M 0M
Δ[] -x +x +x
[]f 0.230-x x x
Then, using the concentration equation, you get
4.5x10^-4 = [H+][NO2-]/[HNO2]
4.5x10^-4 = x*x / .230 - x
However, because the Ka value for nitrous acid is lower than 10^-3, we can assume the amount it dissociates is negligable,
assume 0.230-x ≈ 0.230
4.5x10^-4 = x^2/0.230
Then, we solve for x by first multiplying both sides by 0.230 and then taking the square root of both sides.
We get the final concentrations of [H+] and [NO2-] to be x, which equals 0.01M.
Then to find percent dissociation, you do final concentration/initial concentration.
0.01M/0.230M = .0434 or
≈4.34% dissociation.
The Law of Conservation of Mass dates from Antoine Lavoisier's 1789 discovery that mass is neither created nor destroyed in chemical reactions. ... If we account for all reactants and products in a chemical reaction, the total mass will be the same at any point in time in any closed system.
Answer:
1s² 2s² 2p⁵
Explanation:
The elements of group 17 are called halogens. These are six elements Fluorine, Chlorine, Bromine, Iodine, Astatine. Halogens are very reactive these elements can not be found free in nature. Their chemical properties are resemble greatly with each other. As we move down the group in periodic table size of halogens increases that's way fluorine is smaller in size as compared to other halogens elements. Their boiling points also increases down the group which changes their physical states. i.e fluorine is gas while iodine is solid.
Properties of fluorine:
1. it is yellow in color.
2. it is flammable gas.
3. it is highly corrosive.
4. fluorine has pungent smell.
5. its reactions with all other elements are very vigorous except neon, oxygen, krypton and helium.
6. Its atomic number of 9.
7. its atomic mass is 18.99 amu.
Electronic configuration:
₉F = 1s² 2s² 2p⁵
Answer:
The molar mass (Mm) of the compound is 127.39 g/mole
Explanation:
ΔT = Kf. molality
ΔT = change in temperature = Tfinal - Tinitial = 2.8 - 5.5
Kf = freezing point depression constant = - 4.3 C/m (always negative because temperature is decreasing)
molality = moles of solute/Kg of solvent = mole (n)/(20 x 10^-3 Kg of benzene)
(2.8 - 5.5) = (-4.3) x molality
molality = 0.6279 mole/kg
0.6279 = mole of compound/(20 x 10^-3)
mole of compound = 0.01256 mole
mole (n) = mass (m) divided by Molar mass (Mm)
Molar mass = mass of compound / mole of compound
m/n = 1.6/0.01256 = 127.39 g/mole