Answer:
Freezing point of solution is -4.39°C
Explanation:
Freezing point depression's formula:
ΔT = Kf . m . i
ΔT = Freezing point of pure solvent - Freezing point of solution
0°C - X = 1.86°C/m . m . 2
i = Van't Hoff factor, ions dissolved in solution
MgCl₂ → Mg²⁺ + 2Cl⁻ i = 3 → 1 mol of Mg and 2 mol of chloride
Let's think the molality (mol/kg)
First of all, let's convert the mass of solvent from g to kg
100 g / 1000 = 0.1 kg
Molality (mol/kg) = 0.118 mol / 0.1 kg = 1.18 m
0°C - X = 1.86°C/m . 1.18 m . 2
X = - 4.39°C
An oxidation-reduction (redox<span>) </span>reaction<span> is a type of chemical </span>reaction<span> that involves a transfer of electrons between two species. An oxidation-reduction </span>reaction<span> is any chemical </span>reaction<span> in which the oxidation number of a molecule, atom, or ion changes by gaining or losing an electron.</span>
16 and 6
Explanation:
the top number will be 16 and the bottom number will be 6
Answer:
6. 7870 kg/m³ (3 s.f.)
7. 33.4 g (3 s.f.)
8. 12600 kg/m³ (3 s.f.)
Explanation:
6. The SI unit for density is kg/m³. Thus convert the mass to Kg and volume to m³ first.
1 kg= 1000g
1m³= 1 ×10⁶ cm³
Mass of iron bar
= 64.2g
= 64.2 ÷1000 kg
= 0.0642 kg
Volume of iron bar
= 8.16 cm³
= 8.16 ÷ 10⁶
Density of iron bar
= 7870 kg/m³ (3 s.f.)
7.
Mass
= 1.16 ×28.8
= 33.408 g
= 33.4 g (3 s.f.)
8. Volume of brick
= 12 cm³
Mass of brick
= 151 g
= 151 ÷ 1000 kg
= 0.151 kg
Density of brick
= mass ÷ volume
(3 s.f.)
