Answer:
i. Molar mass of glucose = 180 g/mol
ii. Amount of glucose = 0.5 mole
Explanation:
<em>The volume of the glucose solution to be prepared</em> = 500 
<em>Molarity of the glucose solution to be prepared</em> = 1 M
i. Molar mass of glucose (
) = (6 × 12) + (12 × 1) + (6 × 16) = 180 g/mol
ii.<em> mole = molarity x volume</em>. Hence;
amount (in moles) of the glucose solution to be prepared
= 1 x 500/1000 = 0.5 mole
Delta energy on labelled diagram is attached below
Answer:
A
Explanation:
OH is generally basic, while H is generally acidic so the greater the OH concentration, the more basic the solution will be.
<span>The solution of ethanol will have the greatest increase in boiling point.
The formula for boiling point elevation is:
ΔTb = Kb · bB
where
ΔTb = boiling point elevation
Kb = ebullioscopic constant for the solvent
bB = molarity of the solution
Since in the solute is nonionic, we don't have to worry about the molecules of the solute breaking up into multiple ions, thereby increasing the effective molarity of the solution. So which ever solvent has the highest ebullioscopic constant, will have the greatest increase in boiling point. This constant can be calculated by the equation:
Kb = RTb^2M/ΔHv
where
R = Ideal gas constant
Tb = boiling point of pure solvent
M = Molar mass of solvent
ΔHv = heat of vaporization per mole of solvent
For our purposes, we can ignore the idea gas constant, and instead look at only the boiling point, molar mass, and heat of vaporization. Then calculate Tb^2M/ΔHv So let's do so:
(Note: Not bothering to be precise in molar mass. If the end result is close, then I'll bother. Otherwise, just using nice round numbers).
Water
Boiling point: 373.15 K
Molar mass: 18 g/mol
heat of vaporization: 40660 J/mol
Tb^2M/ΔHv: 61.64
Ethanol
Boiling point: 351.52 K
Molar mass: 46 g/mol
heat of vaporization: 38600 J/mol
Tb^2M/ΔHv: 147.26
The value of Tb^2M/ΔHv is significantly greater for ethanol than it is for water (by more than 2 to 1), so it will have the greatest increase in boiling point.</span>
Answer:
Explanation:
<u>1) Mass of carbon (C) in 2.190 g of carbon dioxide (CO₂)</u>
- atomic mass of C: 12.0107 g/mol
- molar mass of CO₂: 44.01 g/mol
- Set a proportion: 12.0107 g of C / 44.01 g of CO₂ = x / 2.190 g of CO₂
x = (12.0107 g of C / 44.01 g of CO₂ ) × 2.190 g of CO₂ = 0.59767 g of C
<u />
<u>2) Mass of hydrogen (H) in 0.930 g of water (H₂O)</u>
- atomic mass of H: 1.00784 g/mol
- molar mass of H₂O: 18.01528 g/mol
- proportion: 2 × 1.00784 g of H / 18.01528 g of H₂O = x / 0.930 g of H₂O
x = ( 2 × 1.00784 g of H / 18.01528 g of H₂O) × 0.930 g of H₂O = 0.10406 g of H
<u>3) Mass of oxygen (O) in 1.0857 g of pure sample</u>
- Mass of O = mass of pure sample - mass of C - mass of H
- Mass of O = 1.0857 g - 0.59767 g - 0.10406 = 0.38397 g O
Round to four decimals: Mass of O = 0.3840 g
<u>4) Mole calculations</u>
Divide the mass in grams of each element by its atomic mass:
- C: 0.59767 g / 12.0107 g/mol = 0.04976 mol
- H: 0.10406 g / 1.00784 g/mol = 0.10325 mol
- O: 0.3840 g / 15.999 g/mol = 0.02400 mol
<u>5) Divide every amount by the smallest value (to find the mole ratios)</u>
- C: 0.04976 mol / 0.02400 mol = 2.07 ≈ 2
- H: 0.10325 mol / 0.02400 mol = 4.3 ≈ 4
- O: 0.02400 mol / 0.02400 mol = 1
Thus the mole ratio is 2 : 4 : 1, and the empirical formula is: