The correct answer for the question that is being presented above is this one:
Given that:
delta Tb = Kbm Kb H2O = 0.52 degrees C/m
<span>delta Tf = Kfm Kf H2O = 1.86 degrees C/m
</span>
We need to know the formula for Molality.
molality = mol solute / kg solvent
<span>We are given the amount of solute in grams
Since amount of solute is given in moles, we have to convert 25 g NaCl to moles. Divide by molar mass. </span>
<span>25 g NaCl / 58.5 g/mol = 0.427 mol </span>
<span>Then, use the formula for molality. </span>
<span>molality = mol solute / kg solvent </span>
<span>= 0.427 / 1 </span>
<span>= 0.427 m </span>
<span>Use now the formula to get the boiling point.</span>
<span>delta Tb = Kbm </span>
<span>= (0.52)(0.427) </span>
<span>= 0.22C </span>
We know because of DNA testing in general.
Answer:
3. Blue I think
4. Exothermic
5. A reversible reaction is when the products can change back into their original reactants.
Answer:Displacement method
Explanation:
Answer: decreases
The temperature of a gas decreases when the pressure decreases at constant volume
Explanation:
The statement of Pressure Law states that the pressure of a given mass of gas is directly proportional to its absolute temperature provided the volume is kept constant.
Mathematically, it is expressed as
P α T
P = kT
or P/T = k
Thus, the direct proportionality of temperature and pressure makes temperature of a gas decreases when the pressure decreases and increases when pressure increases.