Ide is the answer for the test
Answer:
— 159.6°C
Explanation:
Data obtained from the question include:
V1 (initial volume) = 960L
T1 (initial temperature) = 38°C = 38 + 273 = 311K
V2 (final volume) = 350L
T2 (final temperature) =?
Since the pressure is constant, then Charles' law is in operation. Using the Charles' law equation V1/T1 = V2/T2, we can easily obtain the final temperature as follow:
V1/T1 = V2/T2
960/311 = 350/T2
Cross multiply to express in linear form.
960 x T2 = 311 x 350
Divide both side by 960
T2 = (311 x 350) /960
T2 = 113.4K
Now let us convert 113.4K to a number in celsius scale. This is illustrated below:
°C = K — 273
°C = 113.4 — 273
°C = — 159.6°C
Therefore, the container will have a volume of 350L at — 159.6°C
B
Explanation:
I rember when I learned this in 3rd grade
Answer: 724.71 grams
Explanation:
Volume of solution (v) = 5.1 liters
Concentration of solution (c) = 1.4M
Amount of CuF2 needed (n) = ?
Since concentration (c) is obtained by dividing the amount of solute dissolved by the volume of solvent, hence
c = n / v
make n the subject formula
n = c x v
n = 1.4M x 5.1 Liters
n = 7.14 moles
Since, 7.14 moles of CuF2 (n) is needed, use the molar mass of CuF2 to get the mass in grams.
The atomic masses of Copper = 63.5g;
and Fluorine = 19g
So, I CuF2 = 63.5g + (19g x 2)
= 63.5g + 38g
= 101.5g/mol
Then, apply the formula
Number of moles = mass in grams / molar mass
7.14 moles = m / 101.5 g/mol
m = 7.14 moles x 101.5 g/mol
m = 724.71g
Thus, 724.71 grams of copper (II) fluoride, CuF2, are needed to make 5.1 liters of a 1.4M solution
