Answer:
C. The electron clouds are negatively charged and repel each other as far apart as possible
Explanation:
This is the basis of VSEPR theory.
The angles between the electron clouds determine the shapes of the molecules.
B. and D. are wrong. All electron pairs are negatively charged.
Answer:
3 moles of CO are needed
Explanation:
Given data:
Number of moles of CO used = ?
Mass of Fe produced = 112 g
Solution:
Chemical equation:
Fe₂O₃ + 3CO → 2Fe + 3CO₂
Number of moles of Fe:
Number of moles = mass/ molar mass
Number of moles = 112 g/ 55.85 g/mol
Number of moles = 2.00 mol
Now we will compare the moles of iron and CO.
Fe : CO
2 : 3
Thus, 3 moles of CO are needed.
Answer is: <span>c. Fe</span>₃<span>O</span>₄<span>.
</span>ω(Fe) = 72,360%.
ω(O) = 100% - 72,36% = 27,64%.
For example, if we the mass of compound is 100 g:
m(Fe) = 72,36 g.
n(Fe) = m(Fe) ÷ M(Fe).
n(Fe) = 72,36 g ÷ 55,85 g/mol.
n(Fe) = 1,296 mol.
n(O) = 27,64 g ÷ 16 g/mol.
n(O) = 1,727 mol.
n(Fe) : n(O) = 1,296 mol : 1,727 mol.
n(Fe) : n(O) = 1 : 1,33 or 3 : 4.
Answer:
2H3PO4 +3Ca(OH) 2 = Ca3 (PO4) 2 +6H20
Ammonia is colorless gas with a characteristic smell. Its density is 0.589 times than air which makes it lighter than air. Ammonia can be easily liquefied due to the hydrogen bonding between the molecules. The boiling point is at -33.3 degrees Celsius and the freezing point is at -77.7 degrees Celsius.