Answer:
Solute = 5 mL; solution = 250 mL
Explanation:
The formula for percent by volume is
![\text{Percent by volume} = \dfrac{\text{Volume of solute}}{\text{Volume of solution}}\times 100 \, \%](https://tex.z-dn.net/?f=%5Ctext%7BPercent%20by%20volume%7D%20%3D%20%5Cdfrac%7B%5Ctext%7BVolume%20of%20solute%7D%7D%7B%5Ctext%7BVolume%20of%20solution%7D%7D%5Ctimes%20100%20%5C%2C%20%5C%25)
If you have 250 mL of a solution that is 2 % v/v,
![\begin{array}{rcl}2 \, \% & = & \dfrac{\text{Volume of solute}}{\text{250 mL}}\times 100 \, \%\\\\2 \times \text{ 250 mL} & = & \text{Volume of solute} \times 100\\\text{Volume of solute} & = & \dfrac{2 \times 250\text{ mL}}{100}\\\\ & = & \textbf{5 mL}\\\end{array}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brcl%7D2%20%5C%2C%20%5C%25%20%26%20%3D%20%26%20%5Cdfrac%7B%5Ctext%7BVolume%20of%20solute%7D%7D%7B%5Ctext%7B250%20mL%7D%7D%5Ctimes%20100%20%5C%2C%20%5C%25%5C%5C%5C%5C2%20%5Ctimes%20%5Ctext%7B%20250%20mL%7D%20%26%20%3D%20%26%20%5Ctext%7BVolume%20of%20solute%7D%20%5Ctimes%20100%5C%5C%5Ctext%7BVolume%20of%20solute%7D%20%26%20%3D%20%26%20%5Cdfrac%7B2%20%5Ctimes%20250%5Ctext%7B%20mL%7D%7D%7B100%7D%5C%5C%5C%5C%20%26%20%3D%20%26%20%5Ctextbf%7B5%20mL%7D%5C%5C%5Cend%7Barray%7D)
If there is no change of volume on mixing,
Volume of solution = 250 mL
-Volume of solute = <u> </u><u>5</u><u> </u>
Volume of solvent = 245 mL
Answer:
![FeSO_{4},FeCH_{3}CO,Fe_{2}(SO_{4})_{3},Fe_{2}(CH_{3}CO)_{3}](https://tex.z-dn.net/?f=FeSO_%7B4%7D%2CFeCH_%7B3%7DCO%2CFe_%7B2%7D%28SO_%7B4%7D%29_%7B3%7D%2CFe_%7B2%7D%28CH_%7B3%7DCO%29_%7B3%7D)
Explanation:
Empirical formula of ionic compound formed by two ions
and
is
(for
) of AB (for x = y)
The above empirical formula is in accordance with charge neutrality principle
Here each cation (
and
) can form two ionic compounds by combining with two given anions (
and
).
So the four ionic compounds are: ![FeSO_{4},FeCH_{3}CO,Fe_{2}(SO_{4})_{3},Fe_{2}(CH_{3}CO)_{3}](https://tex.z-dn.net/?f=FeSO_%7B4%7D%2CFeCH_%7B3%7DCO%2CFe_%7B2%7D%28SO_%7B4%7D%29_%7B3%7D%2CFe_%7B2%7D%28CH_%7B3%7DCO%29_%7B3%7D)
Answer:
300 mL
Explanation:
the unit formula of calcium phosphate is Ca3(PO4)2
molar mass of Ca3(PO4)2 = (3×40 + 2×31 + 8×16) g/mol = 310 g/mol
n = m/M = 35 g/(310 g/mol)
c = n/V
V = n/c = [35 g/(310 g/mol)]/0.375 mol/L
V = 0.30 L = 300 mL
We can calculate years by using the half-life equation. It is expressed as:
A = Ao e^-kt
<span>where A is the amount left at t years, Ao is the initial concentration, and k is a constant.
</span>From the half-life data, we can calculate for k.
1/2(Ao) = Ao e^-k(1620)
<span>k = 4.28 x 10^-4
</span>
0.125 = 1 e^-<span>4.28 x 10^-4 (</span>t)
t = 4259 years
The correct answer is From different social and ethnic backgrounds.
Explanation:
The purpose of science studies is to gain an understanding of specific phenomena and use this in the benefit of the world or humanity. Moreover, science is guided by objective methods and these are applied all around the world. This feature allows scientists from all kinds of social and ethnic backgrounds to study the same phenomena and obtain similar results, which is essential for the progress of scientific knowledge. This is exemplified by two different labs in two different countries studying drug absorption because the results of these two studies can be analyzed together to understand drug absorption.
In this context, one factor that contributes to the progress of scientific knowledge is the effort of scientists "from different social and ethnic backgrounds".