Oxygen-8×2=16, sulphur=16
1mole=6.023×10^23molecule=22.4l=32gram
32g=6.023×10^23molecule
1g=6.023×10^23÷32
13.5g=6.023×10^23÷32×13.5
=2.5×10^23 molecule
.°. there are 2.5×10^23 molecule in 13.5g of sulphur dioxide
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Answers:
See below
Step-by-step explanation:
1. Most food energy
(a) Pringles
Heat from Pringles + heat absorbed by water = 0
m₁ΔH + m₂CΔT = 0
1.984ΔH + 100 × 4.184 × 18 = 0
1.984ΔH + 7530 = 0
ΔH = -7530/1.984 = -3800 J/g
(b) Cheetos
0.884ΔH + 418.4 × 13 = 0
ΔH = -5400/0.884 = -6200 J/g
Cheetos give you more food energy per gram.
(c) Snickers
Food energy = 215 Cal/28 g × 4184 J/1 Cal = 32 000 J/g
The food energy from Cheetos is much less than that from a Snickers bar
2. Experimental uncertainty
The experimental values are almost certainly too low.
Your burning food is heating up the air around it, so much of the heat of combustion is lost to the atmosphere.
3. Percent efficiency
Experimental food energy = 3800 J/g
Actual food energy = 150 Cal/28 g × 4184 J/1 Cal = 22 000 J/g
% Efficiency = Experimental value/Actual value × 100 %
= 3800/22 000 × 100 %
= 17 %
When equal volumes of ethanol and water are mixed to form a solution, the entropy of the resulting solution increases. This is because ethanol and water are both polar substances, making them miscible. The solubility of both substances is high because they have similar attractions due to the presence of hydrogen bonding. This means that molecules of water and ethanol freely move with each other, therefore increasing the dispersal, randomness, and disorder (entropy) of the system.
