Answer:
If temperature increases, as it does in most reactions, a chemical change is likely to be occurring. This is different from the physical temperature change. During a physical temperature change, one substance, such as water is being heated.
Explanation:
<span>The correct answer is the first option. Electron is not found in the nucleus of an atom. The sub-atomic particles of an atom are the
proton, electron and the neutron. An electron has a charge of -1 and a
smaller mass than a proton. Proton has the same mass with the neutron. The
ratio between the mass of a proton and an electron is about 2000. An electron
has an equal value but negative charge with the proton.</span>
Answer:
For pure substances, the mass and volume will always be the same or will always change the same way because all substance are the same throughout.
While for mixtures, you can have varying amount of each component therefore mass and volume will not change the same way for substances
Answer:
Mole fraction for C₂₂H₁₉Cl₂NO₃ = 0.0086
Explanation:
Mole fraction remains a sort of concentration. It indicates:
moles of solute / (moles of solute + moles of solvent)
Moles of solute / Total moles.
Solute: Cypermethrin → C₂₂H₁₉Cl₂NO₃
Solvent: Water (PM = 18g/mol)
We calculate moles from solvent: 1000g /18 g/mol = 55.5 moles
We calculate PM for C₂₂H₁₉Cl₂NO₃
12g/mol . 22 + 1g/mol . 19 + 35.45 g/mol . 2+ 14g/mol + 16g/mol . 3 = 416 g/m
Moles of solute: 200 g / 416g/mol = 0.481 moles
Total moles: 0.481 + 55.5 = 55.98 moles
Mole fraction for C₂₂H₁₉Cl₂NO₃ = 0.481 moles / 55.98 moles = 0.0086