Answer:
0.08 mL
Explanation:
The solution of the skin test has a concentration of 0.2% (w/v), which means that there are 0.2 g of the antigen per 100 mL of the solution. If a new solution will be done using it, then this solution will be diluted, and the mass of the antigen added must be the same in the volume taken and at the diluted solution.
The mass is the concentration (in g/mL) multiplied by the volume of the solution (in mL), so, if m is the mass, C the concentration, V the volume, 1 the initial solution, and 2 the diluted:
m1 = m2
C1*V1 = C2*V2
Where
C1 = 0.2 g/100 mL = 0.002 g/mL
V1 = ?
C2 = 0.04 mg/mL = 0.00004 g/mL
V2 = 4 mL
0.002*V1 = 0.00004*4
V1 = 0.08 mL
<span>Molds are created to achieve a
specific design of a material. These materials either came from a process of
having a higher or lower temperature. Therefore, the molder must have thermal
resistant properties. Low melting points means that the material to be shaped
came from a cooler process. Wood and metal have higher thermal conductivity and
therefore can easily be cooled. The wax can turn really hard and can be
unbreakable when present in colder materials due to the lipids present in it. Clay
however can become a mold because of its low melting point.</span>
Answer:
-43.3 °C
Explanation:
To find the temperature, you need to use the Ideal Gas Law equation. The equation looks like this:
PV = nRT
In this formula,
-----> P = pressure (atm)
-----> V = volume (L)
-----> n = moles
-----> R = Ideal Gas Law constant (0.08206 atm*L/mol*K)
-----> T = temperature (K)
By plugging the given values into the equation and simplifying, you can find the temperature. After you get a temperature, you need to convert it into Celsius.
P = 2.88 atm R = 0.08206 atm*L/mol*K
V = 3.76 L T = ? K
n = 0.574 moles
PV = nRT
(2.88 atm)(3.76 L) = (0.574 moles)(0.08206 atm*L/mol*K)T
10.8288 = (0.04710244)T
230. K = T
Kelvin - 273.15 = Celsius
230 K - 273.15 = -43.3 °C
Answer:
<em>H.vap = 6.544 kJ/mol</em>
Explanation:
Clausius-Clapeyron Equation
<em>In P = H.vap / RT</em> where T = 20 + 273 = 293K
H.vap = In P (RT) = In 11 (8.314 x 293) = 6543.861 J/mol = 6.544 kJ/mol
