Both litmus paper and phenolphthalein are used as acid/base (pH) indicators.
Litmus paper:
Litmus paper will turn either blue or red when a drop of solution is added to the paper. Red indicates an acidic solution (pH is <4.5), and blue indicates a basic solution (pH >8.3).
Phenolphthalein:
Phenolphthalein is commonly used during acid/base titrations. When the solution is acidic and the indicator is added, it will remain colorless. If the solution is basic, the phenolphthalein will turn pink.
<h3><u>Answer;</u></h3>
D. Process B, because it is a spontaneous process.
<h3><u>Explanation</u>;</h3>
- A spontaneous process is one that will occur without any energy input from the surroundings.
- A spontaneous reaction may involve an increase or decrease in enthalpy, it may involve an increase or decrease in entropy, but it will always involve a decrease in free energy that is a negative ΔG.
- Therefore; process B is spontaneous since it has a negative ΔG
Answer:
0.116%
Explanation:
efficiency of sterling engine = 1 - ( 55 + 273 )k / ( 95 + 273 ) k
= 1 - ( 328 / 368 ) = 0.10869
<u>Determine how efficient the transfer of energy via flame is </u>
apply this relation ; energy of steady state / energy output ---- ( 1 )
where; <em><u>energy output</u></em> = efficiency of sterling engine * energy
= 0.10869 * 50 = 5.4345 J/sec
<em><u>energy of steady state</u></em> = 1/2 * I * w^2 ------ ( 2 )
I = moment of inertia of engine = 2 * 10^-5 kgm^2
back to equation 2 :
energy of steady state = 1/2 * ( 2 * 10^-5 ) * ( 240 * 2π / 60 )^2
= 630.88 * 10^-5 J /sec
Input values into equation 1
= [ (630.88 * 10^-5 ) / 5.4345 ] * 100
= 0.116%
I think the 3 indicates the number of molecules
Answer:
The pressure exerted by helium on the walls of the container is approximately 760.6 mmHg
Explanation:
The parameters given in the question are;
Amount of moles of helium in balloon = 1.00 mole
Volume of balloon = 22.4 L = 0.0224 m³
Temperature of balloon = 0.00°C = 273.15 K
Therefore, we have the pressure given by the universal gas equation as follows;
P·V = n·R·T
So that
Converting the resultant pressure in pascals, Pa to millimetre mercury, mmHg we have;
1 mmHg = 133.3 Pa
∴ 1 Pa = 1/133.33 mmHg and
101388.646 Pa = 101388.646× 1/133.3 mmHg = 760.604996 mmHg
Therefore the pressure exerted by helium on the container ≈ 760.6 mmHg.
