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.
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Answer:
4. 1.18 mol·L⁻¹
14. See below.
Explanation:
4. Dilution calculation
V₁c₁ = V₂c₂
Data:
V₁ = 200 mL; c₁ = 5.6 mol·L⁻¹
V₂ = 950 mL; c₂ = ?
Calculation:
c₂ = c₁ × V₁/V₂
c₂ = 5.6 mol·L⁻¹ × (200/950) = 1.18 mol·L⁻¹
The new concentration is 1.18 mol·L⁻¹
.
14. Boyle's Law graphs
We can write Boyle's Law as
pV = k or p = k/V or V= k/p
p and V are inversely related.
(a) As pressure increases, volume decreases. Thus, a graph of V vs p is a hyperbola.
(b) p = k/V =k(1/V)
1/V = (1/k)p
y = m x + 0
A graph of 1/V vs p is a straight line.
Answer:
Molar ratio of the compound is 1:1 and the type of hydrate is Mono hydrate.
Explanation:
From the given,
Mass of sodium carbonate 
= 8.85 g
Loss mass 
= 1.28 g
Actual weight of sodium carbonate = 8.85 g - 1.28 g = 7.57 g
Therefore, the compound has only one water molecule.
Molecular formula of the compound is 
an name of the compound is <u>sodium carbonate mono hydrate.</u>
Hence, the type of the compound is Mono hydrate.
Answer:
Both answer choice 2 and answer choice 3 are correct choices.
Explanation:
Biotic factors are living components in an ecosystem. They are living organisms which affect another living component in an ecosystem.
Antibiotic factors are non living components of an ecosystem. They are chemicals which affect living organisms.
The choice 2 is correct. The seeds spread out by mice is a biotic factor interacting with an antibiotic factor
Choice 3 is correct. The seeds in the soil grow into new trees are biotic factors interacting with an antibiotic factor
Explanation:
It represent Alcohol group (—OH)
