An element is a form of matter that is made of only one type of atom
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.
Answer:
a. 1.21M
b. 0.119M
c. 0.00496M
Explanation:
Molarity, M, is an unit of concentration defined as the ratio between moles of solute and liters of solution:
a. 4.35 mol LiCl / 3.60L = 1.21M
b. 29.43gC6H12O6 * (1mol / 180.16g) = 0.1634moles / 1.37L = 0.119M
<em>Molar mass C6H12O6: 180.16g/mol</em>
c. 34.5mg NaCl = 0.0345g * (1mol / 58.44g) = 5.9x10⁻⁴moles / 0.1191L = 0.00496M
Answer:
The Punnett square is a square diagram that is used to predict the genotypes of a particular cross or breeding experiment. ... The diagram is used by biologists to determine the probability of an offspring having a particular genotype.
Explanation:
in biology it predicts the possible offspring provided the features of the mother or father