Answer:
D. Convert the 0.2 kg of NaCl to moles of NaCl
Explanation:
The molality equation looks like this:
Molality = moles of solute / mass (kg) of solvent
In this case, the solute is NaCl and the solution is water. So, if you have been given NaCl in kg, you need to convert it to grams and then to moles in order to plug it into the equation.
Answer:
by which method do you need
Answer:
Only the radiation with a wavelength 0.91 nm can be observed by an X-ray detector.
Explanation:
To answer this question we need to consult the ranges in which x rays are in the electromagnetic spectrum:
The X radiation in the electromagnetic spectrum fall in the region of:
frequency: 3 x 10¹⁶ Hz to 3 x 10¹⁹ Hz (1Hz = 1s⁻¹)
wavelengt: 1 pm to 10 nm
Comparing the values in our question,
0.91 nm will be detected
5.9 x 10¹¹ Hz will not be detected.
Answer:
0.004548 M is the concentration of B at equilibrium at 500 K.
Explanation:
A(aq) ⇆ 2 B(aq)
Initially 3.00 M
At equilibrium 3.00 -x 2x
Equilibrium constant of the reaction at 500 K =
Concentration of A at 500 K at equilibrium , [A] = (3.00 -x )M
Concentration of B at 500 K at equilibrium,[B]= 2x
An expression of equilibrium constant is given as:
![K_c=\frac{[B]^2}{[A]}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%5BB%5D%5E2%7D%7B%5BA%5D%7D)

On solving for x:
x = 0.002274 M
[B] = 2 x = 2 × 0.002274 M = 0.004548 M
[A] = (3-x) = 3 M - 0.002274 M =2.997726 M
0.004548 M is the concentration of B at equilibrium.
Answer:
true
Explanation:
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