Answer:

Explanation:
Hello!
In this case, since the molarity of magnesium chloride (molar mass = 95.211 g/mol) is 1.672 mol/L and we know the density of the solution, we can first compute the concentration in g/L as shown below:
![[MgCl_2]=1.672\frac{molMgCl_2}{L}*\frac{95.211gMgCl_2}{1molMgCl_2}=159.2\frac{gMgCl_2}{L}](https://tex.z-dn.net/?f=%5BMgCl_2%5D%3D1.672%5Cfrac%7BmolMgCl_2%7D%7BL%7D%2A%5Cfrac%7B95.211gMgCl_2%7D%7B1molMgCl_2%7D%3D159.2%5Cfrac%7BgMgCl_2%7D%7BL%7D)
Next, since the density of the solution is 1.137 g/mL, we can compute the concentration in g/g as shown below:
![[MgCl_2]=159.2\frac{gMgCl_2}{L}*\frac{1L}{1000mL}*\frac{1mL}{1.137g}=0.14](https://tex.z-dn.net/?f=%5BMgCl_2%5D%3D159.2%5Cfrac%7BgMgCl_2%7D%7BL%7D%2A%5Cfrac%7B1L%7D%7B1000mL%7D%2A%5Cfrac%7B1mL%7D%7B1.137g%7D%3D0.14)
Which is also the by-mass fraction and in percent it turns out:

Best regards!
Chromium , silver, zinc...
Answer:
Explanation:
NH₄NO₃ = NH₄⁺ +NO₃⁻
heat released by water = msΔ T
m is mass , s is specific heat and ΔT is fall in temperature
= 50 x 4.18 x ( 22 - 16.5 ) ( mass of 50 mL is 50 g )
= 1149.5 J .
This heat will be absorbed by the reaction above .
q for the reaction = + 1149.5 J
2 )
molecular weight of NH₄NO₃ = 80
No of moles reacted = 5/80 = 1 / 16 moles.
3 )
5 g absorbs 1149.5 J
80 g absorbs 1149.5 x 16 J
= 18392 J
= 18.392 kJ.
= + 18.392 kJ
ΔH = 18.392 kJ / mol
Answer -C They are defined by the number of electrons.
An orbital is a function that describes the probability of finding the electron with certain energy at certain distance from the nucleus therefore, it is defined by the number of electrons.