<span>Percentage
by mass is the amount in mass of a component in a mixture per 100 unit of
mass of the total mixture. Percentage by mass is the same as %w/w.
We can determine this by dividing the mass of the solute with the total mass of
the mixture. We calculate as follows:
Percent salt = 1.5 g salt / 30.0 g x 100 = 5% </span>
[H+] in first brand:
4.5 = -log([H+])
[H+] = 10^(-4.5)
[H+] in second brand:
5 = -log[H+]
[H+] = 10^(-5)
Difference = 10^(-4.5) - 10^(-5)
= 2.2 x 10⁻⁵
The answer is A.
Answer:
1. electrons
2. From "Y" to "X"
Explanation:
1. Electrons move between the rod since the electrons are the only charge carriers which are free to move.
2. The particles move from from "Y" to "X" since the electrons are the only charge carriers which are free to move. The positive charge on rod x is due to a deficit of electrons while the negative charge on rod Y is due to the excess of electrons. When the rods come together, the electrons move from "Y" to "X" since the electrons are the only charge carriers which are free to move.
First we have to convert:145 pm = 145 * 10^(-12) m36 cm = 360 mm = 360 * 10^(-3) mn = 360 * 10^(-3) m / 145 * 10^(-12) m = = 360 * 10^(-3) * 10^(12) / 145 = = 2.482758621 * 10^(9) or:2,482,758,621 atoms.
Answer:
molecular weight (Mb) = 0.42 g/mol
Explanation:
mass sample (solute) (wb) = 58.125 g
mass sln = 750.0 g = mass solute + mass solvent
∴ solute (b) unknown nonelectrolyte compound
∴ solvent (a): water
⇒ mb = mol solute/Kg solvent (nb/wa)
boiling point:
- ΔT = K*mb = 100.220°C ≅ 373.22 K
∴ K water = 1.86 K.Kg/mol
⇒ Mb = ? (molecular weight) (wb/nb)
⇒ mb = ΔT / K
⇒ mb = (373.22 K) / (1.86 K.Kg/mol)
⇒ mb = 200.656 mol/Kg
∴ mass solvent = 750.0 g - 58.125 g = 691.875 g = 0.692 Kg
moles solute:
⇒ nb = (200.656 mol/Kg)*(0.692 Kg) = 138.83 mol solute
molecular weight:
⇒ Mb = (58.125 g)/(138.83 mol) = 0.42 g/mol
