Heat required = Q = 40 kcal
<h3>Further explanation</h3>
Given
mass of 500 g ice
Required
Heat required
Solution
The heat to change the phase can be formulated :
- Q = m.Lf (melting/freezing)
- Q = m.Lv (vaporization/condensation)
Lf=latent heat of fusion
Lv=latent heat of vaporization
Lf for water = 334 kj/kg=6.01 kJ/mol = 80 cal/g
Phase change(ice to water)
Q= 500 g x 80 cal/g
Q = 40 kcal
Answer:
MgO + H₂
Explanation:
The products of reaction is MgO and hydrogen gas.
This is a single displacement reaction.
In this reaction, the possibility of the reaction is determined by position of the atoms on the activity series.
Mg is higher than H on the activity series, so it is more reactive and it then displaces the hydrogen in water;
Mg + H₂O → MgO + H₂
Answer:
16.4 °C
Explanation:
Boiling point elevation is the phenomenon in which the boiling point of a solvent will increase when another compound is added to it; meaning that athe resultant solution has a higher boiling point than its pure solvent.
Using the ebullioscopic constant,
ΔT = m * i * Kb
Where,
Δ T is the temperature difference between the boiling point of the solution, Temp.f and boiling point of the pure solvent, Temp.i
Kb is the ebulliscope factor of water = 0.510 °C.kg/mol
i is the van hoffs number = 1
m is the molality in mol/kg.
Calculating the molality of the solution,
Temp.i = 100°C
Temp.f = 104.5 °C
= 4.5/(1*0.510)
= 8.8235 mol/kg
Freezing point depression is defined as the decrease in the freezing point of a solvent on the addition of a solute.
Using the same equation, but kf = 1.86 °C.kg/mol
ΔT = m * i * Kf
Temp.i = freezing point of water = 0°C
Temp.f = (8.8235*1.86) - 0
= 16.412 °C
Freezing point of the solution = 16.4 °C
Explanation:
is used for making ropes, used for climbing rocks and for making parachutes. Their usage shows that nylon fibres have high tensile strength
An: Calculate the molarity of a solution made by adding 120 g of NaOH (40.00 g/mol) to enough water to make 500.0 mL of solution. a) 4.0 M b) 6.0 M c) 1.0 ...
Explanation:
