The moon, man has not been to mars yet
Answer:
chemical energy into thermal energy
Explanation:
The reaction taking place is as follows
2C₂H₂ + 5O₂ = 4CO₂ + 2H₂O + Heat
In this reaction bonds present in acetylene is broken and new bond present in water and carbon dioxide are formed . In the whole process of bond breaking and bond formation , there is net loss of energy and that energy is released as heat energy .
Thus we can say that in the whole process , chemical energy is converted into heat energy .
Set a piece of pH paper in front of each solution before testing to keep organized.
Use a transfer pipet to remove a few drops from the solution to drop onto the paper.
Wait a minute or so before reading color.
Is the correct answer...
Answer:
67,9 L
Explanation:
Boyle's Law indicates that the pressure of a fixed amount of gas at a constant temperature is inversely proportional to the volume of a gas, for a constant amount of gas we can write:
P1V1=P2V2
For the problem:
P1= 1 atm, V1= 12,9 L
P2=0,19 atm, V2=?
Therefore:
V2=P1V1/P2.................... V2=1 atm*12,9L/0,19 atm = 67,9 L
The balloon would occupy a volume of 67,9 L in the upper atmosphere.
Answer:
pH =3.8
Explanation:
Lets call the monoprotic weak acid HA, the dissociation equilibria in water will be:
HA + H₂O ⇄ H₃O⁺ + A⁻ with Ka = [ H₃O⁺] x [A⁻]/ [HA]
The pH is the negative log of the H₃O⁺ concentration, we know the equilibrium constant, Ka and the original acid concentration. So we will need to find the [H₃O⁺] to solve this question.
In order to do that lets set up the ICE table helper which accounts for the species at equilibrium:
HA H₃O⁺ A⁻
Initial, M 0.40 0 0
Change , M -x +x +x
Equilibrium, M 0.40 - x x x
Lets express these concentrations in terms of the equilibrium constant:
Ka = x² / (0.40 - x )
Now the equilibrium constant is so small ( very little dissociation of HA ) that is safe to approximate 0.40 - x to 0.40,
7.3 x 10⁻⁶ = x² / 0.40 ⇒ x = √( 7.3 x 10⁻⁶ x 0.40 ) = 1.71 x 10⁻³
[H₃O⁺] = 1.71 x 10⁻³
Indeed 1.71 x 10⁻³ is small compared to 0.40 (0.4 %). To be a good approximation our value should be less or equal to 5 %.
pH = - log ( 1.71 x 10⁻³ ) = 3.8
Note: when the aprroximation is greater than 5 % we will need to solve the resulting quadratic equation.
