Answer: Within each element square, information on the element's symbol, atomic number, atomic mass, electronegativity, electron configuration, and valence numbers can be found. At the bottom of the periodic table is a two row block of elements that contain the lanthanoids and actinides.
Answer:
- Last choice: <em><u>- 3.72°C</u></em>
Explanation:
The freezing point depression in a solvent is a colligative property: it depends on the number of solute particles.
The equation to predict the freezing point depression in a solvent is:
Where,
- ΔTf is the freezing point depression of the solvent,
- Kf is the cryoscopic molal constant of the solvent, and i is the Van'f Hoff factor, which is the number of ions produced by each unit formula of the ionic compound.
The calcualtions are in the attached pdf file. Please, open it by clicking on the image of the file.
Answer:
2.53 L is the volume of H₂ needed
Explanation:
The reaction is: C₁₈H₃₀O₂ + 3H₂ → C₁₈H₃₆O₂
By the way we can say, that 1 mol of linolenic acid reacts with 3 moles of oxygen in order to produce, 1 mol of stearic acid.
By stoichiometry, ratio is 1:3
Let's convert the mass of the linolenic acid to moles:
10.5 g . 1 mol / 278.42 g = 0.0377 moles
We apply a rule of three:
1 mol of linolenic acid needs 3 moles of H₂ to react
Then, 0.0377 moles will react with (0.0377 . 3 )/1 = 0.113 moles of hydrogen
We apply the Ideal Gases Law to find out the volume (condition of measure are STP) → P . V = n . R . T → V = ( n . R .T ) / P
V = (0.113 mol . 0.082 L.atm/mol.K . 273.15K) 1 atm = 2.53 L
Answer:
2Mg + O₂ ⟶ 2MgO
Explanation:
Step 1. Start with the most complicated-looking formula (O₂?).
Put a 1 in front of it.
Mg + 1O₂ ⟶ MgO
Step 2. Balance O.
We have fixed 2 O on the left. We need 2O on the right. Put a 2 in front of MgO.
Mg + 1O₂ ⟶ 2MgO
Step 3. Balance Mg.
We have fixed 2 Mg on the right-hand side. We need 2 Mg atoms on the left. Put a 2 in front of Mg.
2Mg + 1O₂ ⟶ 2MgO
Every formula now has a coefficient. The equation should be balanced. Let’s check.
<u>Atom</u> <u>On the left</u> <u>On the righ</u>t
Mg 2 2
O 2 2
All atoms are balanced.
The balanced equation is
2Mg + O₂ ⟶ 2MgO
