Answer:
<em> 14, 508J/K</em>
ΔHrxn =q/n
where q = heat absorbed and n = moles
Explanation:
<em>m = mass of substance (g) = 0.1184g</em>
1 mole of Mg - 24g
<em>n</em> moles - 0.1184g
<em>n = 0.0049 moles.</em>
Also, q = m × c × ΔT
<em> Heat Capacity, C of MgCl2 = 71.09 J/(mol K)</em>
<em>∴ specific heat c of MgCL2 = 71.09/0.0049 (from the formula c = C/n)</em>
<em>= 14, 508 J/K/kg</em>
ΔT= (final - initial) temp = 38.3 - 27.2
= 11.1 °C.
mass of MgCl2 = 95.211 × 0.1184 = 11.27
⇒ q = 11.27g × 11.1 °C × <em>14, 508 j/K/kg </em>
<em>= 1,7117.7472 J °C-1 g-1</em>
<em />
<em>∴ ΔHrxn = q/n</em>
<em>=1,7117.7472 ÷ 0.1184 </em>
<em>= 14, 508J/K</em>
Normally, cortisol is present in the body at higher levels in the morning, and at it is lowest at night. Although stress isn’t the only reason that cortisol is secreted into the bloodstream, it has been termed “the stress hormone” because it’s also secreted in higher levels during the body’s stress response and is responsible for several stress-related changes in the body.
Answer:
80mL
Explanation:
Step 1:
Data obtained from the question.
Initial Volume (V1) = 40mL
Initial temperature (T1) = –123°C
Final temperature (T2) = 27°C
Final volume (V2) =..?
Step 2:
Conversion of celsius temperature to Kelvin temperature.
T(K) = T(°C) + 273
Initial temperature (T1) = –123°C =
–123°C + 273 = 150K
Final temperature (T2) = 27°C = 27°C + 273 = 300K
Step 3:
Determination of the final volume.
This can be obtained as follow:
V1/T1 = V2/T2
Initial Volume (V1) = 40mL
Initial temperature (T1) = 150K
Final temperature (T2) = 300
Final volume (V2) =..?
V1/T1 = V2 /T2
40/150 = V2 /300
Cross multiply
150 x V2 = 40 x 300
Divide both side by 150
V2 = (40 x 300) /150
V2 = 80mL
Therefore, the new volume of the gas is 80mL
Answer:
This stiffening process, called Rigor Mortis, has a roughly known time of occurrence and can therefore be used to estimate time of death. In general: If the body feels warm and no rigor is present, death occurred under 3 hours before. If the body feels warm and stiff, death occurred 3-8 hours earlier.
Answer:
Molality, Solvent, Solute, Mole fraction, Molarity.
Explanation:
The expression of concentration that provides the moles of solute per kilograms of solvent is Molality. This in the only expression referred to the solvent.
A solution is made up of 0.15 grams of sodium chloride in 1 liter of water. For this solution, the Solvent is water. When water is present, it is usually considered the solvent.
A solution is made up of 0.15 grams of sodium chloride in 1 liter of water. For this solution, the Solute is sodium chloride. There can be 1 or more solutes in a solution.
If you place 5 moles of sodium chloride and 4 moles of sucrose into 11 moles of water, the Mole fraction of sodium chloride would be 0.25. The mole fraction is equal to the moles of a substance divided by the total number of moles.
A way to express concentration that provides the moles of solute per liter of solution is Molarity.
