Molar mass NaNO3 = 85 g/mol
Volume in liters: 410.0 mL / 1000 => 0.41 L
mass = M x molar mass x V
mass = 1.2 x 85 x 0.41
mass = 41.82 g of NaNO3
1. B
2. B
3. A
4. D
5. A
6. A
Answer:
Explanation:
Just trying to get some points
Answer:
1.12g/mol
Explanation:
The freezing point depression of a solvent for the addition of a solute follows the equation:
ΔT = Kf*m*i
<em>Where ΔT is change in temperature (Benzonitrile freezing point: -12.82°C; Freezing point solution: 13.4°C)</em>
<em>ΔT = 13.4°C - (-12.82) = 26.22°C</em>
<em>m is molality of the solution</em>
<em>Kf is freezing point depression constant of benzonitrile (5.35°Ckgmol⁻¹)</em>
<em>And i is Van't Hoff factor (1 for all solutes in benzonitrile)</em>
Replacing:
26.22°C = 5.35°Ckgmol⁻¹*m*1
4.90mol/kg = molality of the compound X
As the mass of the solvent is 100g = 0.100kg:
4.9mol/kg * 0.100kg = 0.490moles
There are 0.490 moles of X in 551mg = 0.551g, the molar mass (Ratio of grams and moles) is:
0.551g / 0.490mol
= 1.12g/mol
<em>This result has no sense but is the result by using the freezing point of the solution = 13.4°C. Has more sense a value of -13.4°C.</em>
Answer:
8.085x10²¹ atoms
Explanation:
Atomic mass of Fe = 55.845 g/mol
it means ,
1 mole Fe = 55.845 g
1 mole = 6.02x10²³ atoms
so,
55.845g Fe has = 6.02x10²³ atoms
∴0.750 g Fe has = {(6.02x10²³ x 0.750)/55.84} atoms
=8.085x10²¹ atoms
