<span> the electron configuration for the manganese atom [Ne]3s</span>²
Answer:
Chemical that can be mixed with another chemical to reduce the dangerous of a specific chemichal
Answer: 88.2 g
Solution:
1) Chemical equation:
<span>2Al (s) + 3Fe(NO3)2 (aq) → 3Fe (s) + 2Al(NO3)3 (aq)
2) Theoretical molar ratios
2 mol Al : 3 mol Fe(NO3)2 : 3 mol Fe : 2 mol Al(NO3)3
3) Starting mass of pure iron nitrate
% = (mass of iron nitrate / mass of solution) * 100 = 87.5
=> mass of iron nitrate = 87.5 * mass of solution / 100
mass of solution = 325 g
=> mass of iron nitrate = 87.5 * 325 g / 100 = 284.375 g
4) moles of iron nitrate
moles = mass in grams / molar mass
molar mass of Fe(NO3)2 = 179.85 g/mol
moles = 284.375 g/ 179.85 g/mol = 1.58 moles Fe(NO3)2
5) proportion:
x 3 mol Fe
--------------------------- = ----------------------
1.58 mol Fe(NO3)2 3 mol Fe(NO3)2
Clear x:
x = 1.58 mol Fe
6) Convert 1.58 mol Fe into grams
mass = number of moles * atomic mass
atomic mass of iron = 55.845 g / mol
mass = 1.58 moles * 55.845 g/mol = 88.24 g
Rounded to 3 significant figures: 88.2 grams of Fe.
</span>
Answer:
At standard room temperature, ![[{\rm OH^{-}] \approx 2.5 \times 10^{-7}\; \rm M](https://tex.z-dn.net/?f=%5B%7B%5Crm%20OH%5E%7B-%7D%5D%20%5Capprox%202.5%20%5Ctimes%2010%5E%7B-7%7D%5C%3B%20%5Crm%20M)
when ![[{\rm H^{+}] = 4.0 \times 10^{-8}\; \rm M](https://tex.z-dn.net/?f=%5B%7B%5Crm%20H%5E%7B%2B%7D%5D%20%3D%204.0%20%5Ctimes%2010%5E%7B-8%7D%5C%3B%20%5Crm%20M)
.
Explanation:
The following equilibrium goes on in water:
.
The forward reaction is known as the self-ionization of water. The ionization constant of water, 
, gives the equilibrium position of this reaction:
![K_{\rm w} = [{\rm H^{+}] \cdot [{\rm OH^{-}}]](https://tex.z-dn.net/?f=K_%7B%5Crm%20w%7D%20%3D%20%5B%7B%5Crm%20H%5E%7B%2B%7D%5D%20%5Ccdot%20%5B%7B%5Crm%20OH%5E%7B-%7D%7D%5D)
.
At standard room temperature (
), 
. Also, ![[{\rm H^{+}}] = 4.0 \times 10^{-8}\; \rm mol \cdot L^{-1}](https://tex.z-dn.net/?f=%5B%7B%5Crm%20H%5E%7B%2B%7D%7D%5D%20%3D%204.0%20%5Ctimes%2010%5E%7B-8%7D%5C%3B%20%5Crm%20mol%20%5Ccdot%20L%5E%7B-1%7D)
. Substitute both values into the equation and solve for ![[{\rm OH^{-}}]](https://tex.z-dn.net/?f=%5B%7B%5Crm%20OH%5E%7B-%7D%7D%5D)
.
![\begin{aligned} {[}{\rm OH^{-}}{]} &= \frac{K_{\rm w}}{[{\rm H^{+}}]} \\ &\approx \frac{10^{-14}}{4.0 \times 10^{-8}} = 2.5 \times 10^{-7}\end{aligned}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7D%20%7B%5B%7D%7B%5Crm%20OH%5E%7B-%7D%7D%7B%5D%7D%20%26%3D%20%5Cfrac%7BK_%7B%5Crm%20w%7D%7D%7B%5B%7B%5Crm%20H%5E%7B%2B%7D%7D%5D%7D%20%5C%5C%20%26%5Capprox%20%5Cfrac%7B10%5E%7B-14%7D%7D%7B4.0%20%5Ctimes%2010%5E%7B-8%7D%7D%20%3D%202.5%20%5Ctimes%2010%5E%7B-7%7D%5Cend%7Baligned%7D)
.
In other words, in an aqueous solution at standard room temperature, when .
Answer:
Molar mass of MgCO3 = 84.3 g/mol
Explanation:
What is the molar mass of magnesium carbonate.
Molar mass of a substance is defined as the mass of one mole of the substance expressed in grams hence its unit is gram per mole (g/mol)
MgCO3 is a compound and it's molar mass would be the sum of the molar masses of the elements that make up the compound. MgCO3 contains 1 atom of magnesium, one atom of carbon and 3 atoms of oxygen
Molar mass of Magnesium = 24.3g
Molar mass of Carbon =12g
Molar mass of Oxygen = 16g
Molar mass of MgCO3 will be
24.3 + 12 + 16×3
= 24.3 + 12 +48 = 84.3 g/mol
Molar mass of MgCO3 = 84.3 g/mol
