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 %
Answer:
A flame test of a colorless solution gives a bright yellow color. When reacted with AgNO, a white precipitate forms that dissolves when HNO, is added.
Answer:
After 26.0s, the concentration of HI decreases from 0.310M to 0.0558M.
Explanation:
Based on the reaction of the problem, you have as general kinetic law for a first-order reaction:
ln[HI] = -kt + ln [HI]₀
<em>Where [HI] is actual concentration after time t, </em>
<em>k is rate constant </em>
<em>and [HI]₀ is initial concentration of the reactant.
</em>
Initial concentration of HI is 0.310M,
K is 0.0660s⁻¹,
And the actual concentration is 0.0558M:
ln[HI] = -kt + ln [HI]₀
ln[0.0558M] = -0.0660s⁻¹*t + ln [
0.310M]
-1.7148 = -0.0660s⁻¹*t
26.0s = t
<h3>After 26.0s, the concentration of HI decreases from 0.310M to 0.0558M</h3>
<em />
Henry's Law is written in equation as:
C = kP
where
C is the concentration
k is the Henry's law constant
P is the partial pressure
This law is applied to soluble gases in liquids. At a certain temperature, there is a specific value of the Henry's Law constant. The C represents the solubility. Hence, we solve for C.
C = (<span>6.26×10</span>⁻⁴ <span>mol/(L⋅atm))*(2.85 atm)
C = 0.0017841 mol/L</span>
