The answer would be A will increase and T <span>will decrease.
The product of this reaction emits red light because it absorbs green and blue light. As the reaction occurs, the concentration of the product increase. This will makes absorbance of green and blue light increases and the solution will become redder.</span>
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.
CO2 and NaCl are both compounds
As long as the equation in question can be expressed as the sum of the three equations with known enthalpy change, its 
can be determined with the Hess's Law. The key is to find the appropriate coefficient for each of the given equations.
Let the three equations with given be denoted as (1), (2), (3), and the last equation (4). Let 
, 
, and 
be letters such that 
. This relationship shall hold for all chemicals involved.
There are three unknowns; it would thus take at least three equations to find their values. Species present on both sides of the equation would cancel out. Thus, let coefficients on the reactant side be positive and those on the product side be negative, such that duplicates would cancel out arithmetically. For instance, 
shall resemble the number of 
left on the product side when the second equation is directly added to the third. Similarly
Thus
and
Verify this conclusion against a fourth species involved- 
for instance. Nitrogen isn't present in the net equation. The sum of its coefficient shall, therefore, be zero.
Apply the Hess's Law based on the coefficients to find the enthalpy change of the last equation.
Answer:
The answer to your question is pH = 1.45
Explanation:
Data
pH = ?
Volume 1 = 200 ml
[HCl] 1 = 0.025 M
Volume 2 = 150 ml
[HCl] 2 = 0.050 M
Process
1.- Calculate the number of moles of each solution
Solution 1
Molarity = moles / volume
-Solve for moles
moles = 0.025 x 0.2
result
moles = 0.005
Solution 2
moles = 0.050 x 0.15
-result
moles = 0.0075
2.- Sum up the number of moles
Total moles = 0.005 + 0.0075
= 0.0125
3.- Sum up the volume
total volume = 200 + 150
350 ml or 0.35 l
4.- Calculate the final concentration
Molarity = 0.0125 / 0.35
= 0.0357
5.- Calculate the pH
pH = -log [H⁺]
-Substitution
pH = -log[0.0357]
-Result
pH = 1.45
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