Answer:
chemical change
Explanation:
because physical is like if something is happening inside your body
BTW
I hope this helps
<u>Given:</u>
Mass of solvent water = 4.50 kg
Freezing point of the solution = -11 C
Freezing point depression constant = 1.86 C/m
<u>To determine:</u>
Moles of methanol to be added
<u>Explanation:</u>
The freezing point depression ΔTf is related to the molality m through the constant kf, as follows:
ΔTf = kf*m
where ΔTf = Freezing point of pure solvent (water) - Freezing pt of solution
ΔTf = 0 C - (-11.0 C) = 11.0 C
m = molality = moles of methanol/kg of water = moles of methanol/4.50 kg
11.0 = 1.86 * moles of methanol/4.50
moles of methanol = 26.613 moles
Ans: Thus around 26.6 moles of methanol should be added to 4.50 kg of water.
Answer:
Water: H2O --> [H+] + [OH-]
Ethyl alcohol: C2H5OH --> [C2H5O-] + [H+]
Explanation:
Dipole-dipole force is observed when an ionic compound ionizes (forms ions), revealing its slightly positive ion and slightly negatively ion.
The chemical formula of Water is H2O.
H2O --> [H+] + [OH-]
The chemical formula of ethyl alcohol is C2H5OH.
C2H5OH --> [C2H5O-] + [H+]
Note the positive and negative parts of both water and ethyl alcohol as expressed in the equations above.
Silicon is the element having a mass of 28.09 g
<u>Explanation</u>:
- Silicon is the element having an atomic mass of 28.09 g / mol. So 28.09 g of silicon contains 6.023
10^23 atoms. One mole of each element can produce one mole of compound.
- The Atomic weight of an element can be determined by the number of protons and neutrons present in one atom of that element. So atomic weight expressed in grams always contain the same number of atoms( 6.023 10^23).
- Avagadro number is the number of atoms of 1 mole of any gas at standard temperature and pressure. It has been determined that 6.023 10^23 atoms of an element are equal to the average atomic mass of that element.
Answer:
As the pressure decreases, the amount of oxygen available to breathe also decreases. Atmospheric pressure is an indicator of weather. When a low-pressure system moves into an area, it usually leads to cloudiness, wind, and precipitation. High-pressure systems usually lead to fair, calm weather.
