2Al (s) + 3Fe(NO3)2 (aq) → 3Fe (s) + 2Al(NO3)3 (aq)
Find the pure amount of iron nitrate solution:
325 g x 87.5% = 284.375 g
Convert 284.375g into mols by dividing by molar mass of the iron nitrate solution
Molar mass of iron nitrate = 55.85 g/mol + 2x14g/mol + 6x16g/mol = 179.85 g/mol
Moles of iron nitrate = 284.375 g / 179.85 g/mol = 1.58
Stoichiometry
3 mols of iron nitrate / 3 mols of iron = 1.58 mols of iron nitrate / x mols of iron
x = 1.58 mols of iron.
Convert that in grams by multiplying by the molar mass of iron
grams of iron = 1.58 mol x 55.85 g/mol = 88.24 g
Answer:
- C-B
- C-C
- C-N
- C-O
- C-F
Explanation:
As we move along to the <u>right in the same period, the electronegativity</u> and <u>the effective nuclear charge values are higher.</u>
The tendency is that <em>the higher these values are, the shorter the bonds will be</em>.
With that information in mind, and looking at the periodic table, the order would be:
- C-B
- C-C
- C-N
- C-O
- C-F
Where the C-F bond is the shortest among them.
Weighs 0.001836 gram per cubic centimeter or 1.836 kilogram per cubic meter
Try to see if this helps
Answer: 4.21×10⁻⁸
Explanation:
1) Assume a general equation for the ionization of the weak acid:
Let HA be the weak acid, then the ionization equation is:
HA ⇄ H⁺ + A⁻
2) Then, the expression for the ionization constant is:
Ka = [H⁺][A⁻] / [HA]
There, [H⁺] = [A⁻], and [HA] = 0.150 M (data given)
3) So, you need to determine [H⁺] which you do from the pH.
By definition, pH = - log [H⁺]
And from the data given pH = 4.1
⇒ 4.10 = - log [H⁺] ⇒ [H⁺] = antilog (- 4.10) = 7.94×10⁻⁵
4) Now you have all the values to calculate the expression for Ka:
ka = 7.94×10⁻⁵ × 7.94×10⁻⁵ / 0.150 = 4.21×10⁻⁸
Answer:
The minimum number of boxes of pencils to be ordered is 630 boxes.
Explanation:
Since a pupil uses averagely 9.3 pencils
and a box contains 12 pencils,
the school enrollment is also 812
school's enrollment x average use of pencil per student
__________________________________________
number of pencils in a box
812 x 9.3 = 7551.6
7551.6 /12 = 629.3
Having a total number of 630 boxes of pencils to be ordered.
