Methods Of Separating Mixtures
Handpicking.
Threshing.
Winnowing.
Sieving.
Evaporation.
Distillation.
Filtration or Sedimentation.
Separating Funnel.
Answer:
The correct row is B.
Explanation:
The formation of the magnesium ion, Mg²⁺, comes from the removal of 2 electrons from the valence shell of the magnesium atom.<em> </em>Since the remotion is of electrons, the nucleus of the atom remains the same, so the number of protons and the number of neutrons does not change.<em> </em>
If the number of proton change, then the atom also change, since the identity of an atom is related to the atomic number which is the same to the proton number.
Now, if the number of neutrons changes, then we would be in the presence of an isotope of the magnesium atom.
Therefore, the correct row is B.
I hope it helps you!
<span>Wave A will have a higher pitch than wave B.. This is not true becasue b has the higher PITCH becasue it's closer together.
Wave B will have a lower pitch than wave A... This basically A but worded differently.
Wave A will have a louder sound than wave B... This is CORRECT becasue it's louder the waver are bigger, so it's louder. But it has a lower pitch, 2 different things.
Wave B will have a louder sound than wave A. False..</span><span />
To solve this problem, we assume ideal gas so that we can
use the formula:
PV = nRT
since the volume of the flask is constant and R is
universal gas constant, so we can say:
n1 T1 / P1 = n2 T2 / P2
1.9 mol * (21 + 273 K) / 697 mm Hg = n2 * (26 + 273 K) /
841 mm Hg
<span>n2 = 2.25 moles</span>
Answer:
3) NaCl.
Explanation:
<em>∵ ΔTf = iKf.m</em>
where, <em>i</em> is the van 't Hoff factor.
<em>Kf </em>is the molal depression freezing constant.
<em>m</em> is the molality of the solute.
<em>The van 't Hoff factor is the ratio between the actual concentration of particles produced when the substance is dissolved and the concentration of a substance as calculated from its mass. </em>
<em></em>
- For most non-electrolytes dissolved in water, the van 't Hoff factor is essentially 1.
<em>So, for sugar: i = 1.</em>
<em>∴ ΔTf for sugar = iKf.m = (1)(Kf)(2.0 m) = 2 Kf.</em>
<em></em>
- For most ionic compounds dissolved in water, the van 't Hoff factor is equal to the number of discrete ions in a formula unit of the substance.
For NaCl, it is electrolyte compound which dissociates to Na⁺ and Cl⁻.
<em>So, i for NaCl = 2.</em>
<em>∴ ΔTf for NaCl = iKf.m = (2)(Kf)(1.0 m) = 2 Kf.</em>
<em></em>
<em>So, the right choice is: 3) NaCl.</em>
<em></em>
