Answer:
volume is 7.0 liters
Explanation:
We are given;
- Molarity of the aqueous solution as 2.0 M
- Moles of the solute, K₂S as 14 moles
We are required to determine the volume of the solution;
We need to know that;
Molarity = Moles ÷ volume
Therefore;
Volume = Moles ÷ Molarity
Thus;
Volume of the solution = 14 moles ÷ 2.0 M
= 7.0 L
Hence, the volume of the molar solution is 7.0 L
Answer:
The correct answer to this problem is B. 7.0 X 10^-8 meters
Explanation:
To solve this problem, we have to use the following equation:
c = λν, or speed of light = wavelength*frequency
If we substitute in the values we are given by the problem, we get:
3.00 * 10^8 m/s = (4.3 * 10^15 Hz)*(wavelength)
wavelength = 6.98 * 10^-8 m
Since the given value has 2 significant figures, our answer should similarly include two significant figures since the operation in the problem was multiplication.
Therefore, the answer is B. 7.0 X 10^-8 meters.
Hope this helps!
Answer:
The base must be ethylamine.
Explanation:
The pH of solution of a weak base gives us an idea about the Kb of the base.


![pOH=-log[OH^{-}]](https://tex.z-dn.net/?f=pOH%3D-log%5BOH%5E%7B-%7D%5D)
![[OH^{-}]=0.0062M](https://tex.z-dn.net/?f=%5BOH%5E%7B-%7D%5D%3D0.0062M)
The relation between Kb and hydroxide ion concentration is:
![Kb=\frac{[OH^{-}]^{2}}{[base]}](https://tex.z-dn.net/?f=Kb%3D%5Cfrac%7B%5BOH%5E%7B-%7D%5D%5E%7B2%7D%7D%7B%5Bbase%5D%7D)

Thus the weak base must be ethylamine.
Answer:
D.) 1.71 M NaCl
Explanation:
Molarity equation: M= n/v
n= moles of solute
v=liters of solution
NaCl= 58.443 g/mol
30g NaCl / 58.443g/mol = 0.5133(this is n)
0.5133 mols/0.300 L=1.71115674 M