Answer: all other conditions equal, the rate evaporation of a contained liquid will be slower than the rate of evaporation of an uncontained liquid.
Justification:
1) The rate of evaporation increases as the surface area of the liquid (relative to the whole content) increases. This is, the greater the surface is the faster the evaporation.
2) That is so because the higher the surface of the liquid the more the number of particles in the liquid that are in contact with the surrounding air and so the more the particles will escape from the liquid to the air (which is what evaporation is).
3) A liquid contained will take the form of the container, so part of the liquid wil remain below the surface, while an uncontained liquid will spread all over the surface and so pratically all the liquid is in contact witht the air surrounding it.
Answer:
pH = 9.03
Explanation:
The equilibrium of the NH₄Cl / NH₃ buffer in water is:
NH₃ + H₂O ⇄ NH₄⁺ + OH⁻
Initial moles of both NH₃ and NH₄⁺ are:
0.100L ₓ (0.20 mol / L) = <em>0.0200 moles </em>
The NH₃ reacts with HCl producing NH₄⁺, thus:
NH₃ + HCl → NH₄⁺ + Cl⁻
<em>That means, moles of HCl added to the solution are the same moles are consumed of NH₃ and produced of NH₄⁺</em>
Moles added of HCl were:
0.025L ₓ (0.20mol / L) = 0.0050 moles of HCl. Thus, final moles of NH₃ and NH₄⁺ are:
NH₃: 0.0200 moles - 0.0050 moles = 0.0150 moles
NH₄⁺: 0.0200 moles + 0.0050 moles = 0.0250 moles.
Using H-H equation for bases:
pOH = pKb + log [NH₄⁺] / [NH₃]
<em>Where pKb is -log Kb =</em><em> 4.745</em><em>.</em>
Replacing:
pOH = 4.745 + log 0.0250mol / 0.0150mol
pOH = 4.967
As pH = 14- pOH
<em>pH = 9.03</em>
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Answer:
Explanation:
Given that,
Mass of sample, m = 996.9 g
The change in temperature of the sample, 
Heat produced, Q = 62.9 calories = 263173.6 J
The heat released by a sample due to change in temperature is given by :
Where
c is the specific heat capacity
So,
So, the specific heat of ethanol is equal to 
.
The answer is the first choice, <u>840 candies</u>.
1st you pour the mixture<span> through a filter to remove the larger </span>pebbles<span>. Next, add water to dissolve the salt and then filter out the </span>pepper the last thing you do <span>evaporate the water to leave the salt behind.</span>
