Answer:
a) 0,5
Explanation:
If x=6 and y=2, then (2x-4y)/(x+y)=(2*6-4*2)/(6+2)=(12-8)/8=4/8= 0,5
Answer:
The freezing point of the solution is -1.4°C
Explanation:
Freezing point decreases by the addition of a solute to the original solvent, <em>freezing point depression formula is:</em>
ΔT = kf×m×i
<em>Where Kf is freezing point depression constant of the solvent (1.86°C/m), m is molality of the solution (Moles CaBr₂ -solute- / kg water -solvent) and i is Van't Hoff factor.</em>
Molality of the solution is:
-moles CaBr₂ (Molar mass:
189.9g ₓ (1mol / 199.89g) = 0.95 moles
Molality is:
0.95 moles CaBr₂ / 3.75kg water = <em>0.253m</em>
Van't hoff factor represents how many moles of solute are produced after the dissolution of 1 mole of solid solute, for CaBr₂:
CaBr₂(s) → Ca²⁺ + 2Br⁻
3 moles of ions are formed from 1 mole of solid solute, Van't Hoff factor is 3.
Replacing:
ΔT = kf×m×i
ΔT = 1.86°C/m×0.253m×3
ΔT = 1.4°C
The freezing point of water decreases in 1.4°C. As freezing point of water is 0°C,
<h3>The freezing point of the solution is -1.4°C</h3>
<em />
Answer:
0.15 M
Explanation:
14.6/46.07g/mol = 0.316 mol Ethanol.
0.316/2.1= 0.15 M
Answer:
0.0451 mol FeCl₂
General Formulas and Concepts:
<u>Chemistry - Atomic Structure</u>
- Reading a Periodic Table
- Using Dimensional Analysis
Explanation:
<u>Step 1: Define</u>
5.72 g FeCl₂
<u>Step 2: Identify Conversions</u>
Molar Mass of Fe - 55.85 g/mol
Molar Mass of Cl - 35.45 g/mol
Molar Mass of FeCl₂ - 55.85 + 2(35.45) = 126.75 g/mol
<u>Step 3: Convert</u>
<u />
= 0.045128 mol FeCl₂
<u>Step 4: Check</u>
<em>We are given 3 sig figs. Follow sig fig rules and round.</em>
0.045128 mol FeCl₂ ≈ 0.0451 mol FeCl₂
D all of the above because it has all of them at the crust
