100.4 degree celsius is the temperature of the water having non-electrolyte.
The correct answer is b.
Explanation:
Data given:
mass of non-electrolyte solute = 31.65 grams
volume of water = 220 ml or 0.22 litres
molar mass of solute = 180.18 grams/mole
density of water = 1 gm/mole
Boiling point of water = 100 degrees celsius
molality = ?
Kb for water = 0.51
boiling point elevation or temperature of hot water,T =?
Formula used:
T = mKb equation 1
number of moles of non electrolyte =
number of moles = 0.17 moles
molality =
molality = 0.77 M
putting the values in equation 1
T = 0.77 X 0.51
T = 0.392 degree celsius. is the elevation in temperature when solute is added.
Temperature of the hot water = 100 +0.392
= 100.392 degree celsius.
The First Two Are Correct Since They Give Off Light
Answer:
Magnesium ribbon
Explanation:
The mole of a substance is a quantity that contains the Avogadro's number of particles.
This Avogadro's number of particles = 6.02 x 10²³particles
It is known that 1 mole of any substance contains 6.02 x 10²³particles
So, from the given choices, the object with the highest number of moles will contain the highest amount of particles.
Magnesium ribbon with 0.871mole will contain the highest number of particles;
Number of particles = 0.871 x 6.02 x 10²³particles = 5.24 x 10²³particles
Answer:
Explanation:
<u>1) Data:</u>
a) mass of solute = ?
b) volume of solution = 1.25 liter
c) M = 2.92 mol/liter
d) solute NaOH
<u>2) Formulae:</u>
<u />
a) Molarity, M = number of moles of solute / volume of solution in liters
b) mass in grams = molar mass × number of moles
<u>3) Solution:</u>
a) <u>Calculate number of moles of solute</u>:
- M = number of moles of solute / volume of solution in liters
⇒ number of moles of solute = M × volume of solution in liters
⇒ number of moles of solute = 2.92 mol/liter × 1.25 liter = 3.65 mol
b) <u>Molar mass of NaOH = 39.997 g/mol </u>(you can take this number from internet or calculate it using the atomic masses of Na, O, and H).
c) <u>Calculate the mass of solute:</u>
- mass in grams = molar mass × number of moles = 39.997 g/mol × 3.65 mol = 145.98905 g = 146. g
The answer must be reported with 3 significant figures, so it is 146. g.