I think Intramolecular forces are being weakened
D. Hydrogen chemical bonds are found within water molecules.
Answer:
- <em><u>A physical change has occurred, with no energy change.</u></em>
Explanation:
When a pencil lead is broken there is not change of any chemical properties, therefore it is not a chemical change, but just a physical change. In this case the change is just the number of pieces and dimensions.
Chemical changes always involve the formation of new different substances; the bonds between the atoms of the starting substances (reactants) breake and new bonds are formed leading to new substances (products) with different chemical composition (arrange of atoms). Chemical changes occur through chemical reactions.
Hence, if there is not change on the chemical composition, you think on physical changes. Physical changes include change in shape, size, state of matter (e.g. solid, liquid, gas). In the case of a pencil lead breaking, it is a change in shape and size.
Also, since energy has not been absorbed or released during the change, the energy of the pencil lead before having been broken is equal to the sum of the energies of the pieces of pencil lead obtained. So, this is a physical change with no energy changes.
Some examples of physical changes that include change in energy are the change of state (e.g. solid to liquid or liquid to gas) and the dissolution of a compound.
Answer:
the reported molar concentration of the sodium hydroxide solution will be too high.
Explanation:
The term "standardization" in science or in analytical Chemistry simply means the process involved in the determination of a standard or the concentration of a particular substance.
One of the advantages and the most important of the advantages of Standardization is that it Helps in making sure that we get a result with the least error.
So, let me explain the answer. The reported molar concentration of the sodium hydroxide solution will be TOO HIGH because the potassium hydrogen phthalate is NOT completely dry. The weight of the moisture will create an additional weight which will increase the weight of potassium hydrogen phthalate in the solution
Answer:
The correct answer is HOF gas.
Explanation:
Based on the given information, the helium atoms effuses three times faster in comparison to the gas X.
The rate of effusion is determined by,
r is inversely proportional to 1/√M, here M is the molecular mass of the gas.
and r is inversely proportional to 1/t, here t is the time taken for effusion.
Thus, t is directly proportional to √M
The molecular mass of He is 4.
tHe = tX/3 (Here tx is the time taken for gas X)
The molecular mass of X is not known.
tX/tHe =√Mx/MHe
3 = √Mx/4
By squaring both the sides we get,
9 = Mx/4
Mx = 36
36 is the molecular mass of gas HOF, that is, (1+16+19 = 36). Hence, the gas X is 36.
