Colligative
properties calculations are used for this type of problem. Calculations are as
follows:<span>
ΔT(freezing point) = (Kf)m
ΔT(freezing point)
= 1.86 °C kg / mol (0.50 mol/kg)
ΔT(freezing point) = 0.93 °C
Tf - T = 0.93 °C
<span>T = -0.93 °C</span></span>
<span>No of moles of Fe = Mass / Relative molar mass of Fe. So no of moles = 89.4/ 55.845 = 1.60. The. Chemical reaction is represented as follows. 4 Fe + 3 O2 which gives 2Fe2 O3 . This means that 4 atoms of Iron reacts with 3 atoms of Oxygen to produce Iron oxide. Hence 1.60*4 moles of Fe will need to react 1.6 * 3 moles of Oxygen to produce 2 moles of Iron oxide. Hence 4.8 moles of Oxygen will be required.</span>
<h2>The required option d) "specific heat" is correct.</h2>
Explanation:
- To raise the temperature of any substance or material of certain mass to respective temperature it requires some amount of heat.
- Specific heat is the amount of heat necessary to raise the temperature of the substance of 1 gram to 1 Kelvin.
- It is the amount of heat which is required to raise the temperature per unit mass to per unit temperature.
- Thus, the required "option d) specific heat" is correct.
Answer:
7. .........................
