The answer you are looking for is "bromine". Hope this helps!
The chemical reaction is expressed as:
2H2 + O2 = 2H2O
To determine the amount of oxygen used in the reaction, we use the amount of water produced and the relation of the substances in the reaction we do as follows:
209 g H2O ( 1 mol / 18.02 g ) ( 1 mol O2 / 2 mol H2O ) ( 32 g / 1 mol ) = 185.57 g O2
To cool 156 g of water from 42.9 °C to 20.5 °C, 101 g of CF₂Cl₂ are required.
CF₂Cl₂ is a refrigerant. When it is evaporated, it absorbs heat from water, which cools.
<h3>What is evaporation?</h3>
Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase.
- Step 1: Calculate the heat released by water.
We will use the following expression.
Qw = c × m × ΔT = (4.184 J/g.°C) × 156 g × (20.5 °C - 42.9 °C)
Qw = -14.6 kJ
where,
- Qw is the heat released by water.
- c is the specific heat of water.
- m is the mass of water.
- ΔT is the change in the temperature of water.
If water releases 14.6 kJ of heat, CF₂Cl₂ absorbs 14.6 kJ of heat (Qr = 14.6 kJ).
- Step 2: Calculate the mass of the refrigerant required.
We will use the following expression.
Qr = ΔH°evap × m
m = Qr/ΔH°evap = 14.6 kJ / (0.144 kJ/g) = 101 g
where,
- Qr is the heat absorbed by the refrigerant.
- ΔH°evap is the heat of vaporization of the refrigerant.
- m is the mass of the refrigerant.
To cool 156 g of water from 42.9 °C to 20.5 °C, 101 g of CF₂Cl₂ are required.
Learn more about evaporation here: brainly.com/question/25310095
I need more information to be able to answer this question
