Answer: 1 mole of the substance is equal to its molar mass or vice versa.
Explanation: Example: 18 g H2O x 1 mole H2O / 18g H2O = 1 mole H2O
B-it does. It demonstrate the ability to move in response to environmental stimuli
Answer:
128.98 g/Mol
Explanation:
ΔTb = Kb * m * i
Where;
ΔTb = boiling point elevation
Kb = boiling point constant
m = molality of the solution
i = Van't Hoff factor
Hence;
Where molality = number of moles of solute/mass of solvent in Kg
Number of moles of solute = mass/Molar mass
So;
80.61 - 80.10 = 2.53 * 13g/M/0.5 * 1
Where M is the molar mass of the solute
0.51 = 2.53 * 13g/M/0.5
0.51 = 2.53 * 13/M * 1/0.5
0.51 = 32.89/M * 1/0.5
0.51 * 0.5 = 32.89/M
0.255 M = 32.89
M = 32.89/0.255
M= 128.98 g/Mol
Answer:
1,100 J.
Explanation:
- The amount of heat added to a substance (Q) can be calculated from the relation:
<em>Q = m.c.ΔT.
</em>
where, Q is the amount of heat released from ethanol cooling,
m is the mass of ethanol (m = 50.0 g),
c is the specific heat of ethanol in the gas phase, since the T is cooled above the boiling point (c = 2.0 J/g °C),
ΔT is the temperature difference (final T - initial T) (ΔT = 79.0 °C – 90.0 °C = - 11.0 °C).
<em>∴ Q = m.c.ΔT</em> = (50.0 g)(2.0 J/g °C)(- 11.0 °C) = <em>- 1100 J.</em>
<em>The system releases 1100 J.</em>
