Answer:
Positive: a and b
Negative: c
Explanation:
The entropy (S) is the measure of the randomness of the system, and it intends to increase. The randomness can be determined by the energy of the molecules, their velocity and how distance they are between the other molecules.
When the entropy increases, ΔS is positive, when the entropy decreases, ΔS is negative. So, when gasoline mix with air in a car engine, the process intends to continue, the randomness increases and ΔS is positive. When hot air expands, the distance between the molecules increases, so ΔS is positive.
But, when humidity condenses, the molecules stay closer, so there's a decrease in the randomness, then ΔS is negative.
There are 674 mg of calcium carbonate in a Rolaids tablet
<h3>Further explanation</h3>
Reaction
CaCO₃ + 2HCl ⇒ CaCl₂ + CO₂ +H₂O
V HCl = 24.65 ml
M HCl = 0.547
mol HCl :
ratio mol CaCO₃ : HCl = 1 : 2, so mol CaCO₃ :
mass of CaCO₃ (MW=100~g/mol) :
The density of the unknown metal, given the data is 1.67 g/mL
<h3>What is density? </h3>
The density of a substance is simply defined as the mass of the subtance per unit volume of the substance. Mathematically, it can be expressed as
Density = mass / volume
With the above formula, we can determine the density of the unknown metal. Details below:
<h3>How to determine the density </h3>
- Mass of unknown metal = 20 - 0 = 20 g
- Volume of unknown metal = 12 - 0 = 12 mL
- Density of unknown metal =?
Density = mass / volume
Density of unknown metal = 20 / 12
Density of unknown metal = 1.67 g/mL
Thus, the density of unknown metal is 1.67 g/mL
Learn more about density:
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Answer:
Percent error = 20%
Explanation:
The percent error is calculated using the following equation:
Percent error = |(approximate value - exact value)| / (exact value) x 100%
In this problem, the approximate value was 184 mL and the exact value was 230.0 mL
Percent error = |(184 mL - 230.0 mL)| / (230.0 mL) x 100% = 20%
