Answer:
2Li + F₂ → 2LiF
Explanation:
The reaction expression is given as:
Li + F₂ → LiF
We are to balance the expression. In that case, the number of atoms on both sides of the expression must be the same.
Let use a mathematical approach to solve this problem;
Assign variables a,b and c as the coefficients that will balance the expression:
aLi + bF₂ → cLiF
Conserving Li: a = c
F: 2b = c
let a = 1, c = 1 and b = 
Multiply through by 2;
a = 2, b = 1 and c = 2
2Li + F₂ → 2LiF
Answer: When a pair of electrons is shared equally between two atoms, the bond formed is called a: pure covalent bond.
I have used the word pure to enphatize that the pair of electrons is shared equally. Some, bonds share the electrons unequally, yet they are covalent but they are polar. When the pair is shared equally the bond is purely covalent.
Also, you must know that covalent bonds may be single (one pair of electrons is shared), double (two pair of electrons are shared) or triple (three pair of electrons are shared).
<span>0.453 moles O2 is the solution</span>
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:
0.0761.
0.0059.
Explanation:
Hello!
In this case, since the writing of numbers in standard notation given the scientific notation requires adding zeros to the left of the first nonzero digit, for the first number, we need to add two zeros as seven is the third digit position:
0.0761.
Next, we need to add three zeros as 5 would be the fourth digit:
0.0059.
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