Answer:
e) pH is independent of concentration.
Explanation:
a) It is a mixture of a weak acid and its conjugate base. <em>TRUE. </em>A buffer is defined as a mixture of a weak acid and its conjugate base or a weak base and its conjugate acid.
b) Resists pH changes because it reacts with added acid or base. <em>TRUE. </em>Thermodynamically, the reaction of added acid or base is faster with the buffer mixture than with H⁺ or OH⁻ ions of the solutions.
c) The maximum buffer capacity is at pH = pKa. <em>TRUE. </em>The buffer capacity is pka±1. For this, buffer capacity is maximum in pka.
d) pH is dependent on the solution ionic strength and temperature. <em>TRUE.</em> Ionic strength and temperature are factors that influence concentrations of ions in solutions as the H⁺ ion that is the responsible
e) pH is independent of concentration. <em>FALSE. </em>pH in a buffer depends completely of concentrations of the acid and its conjugate base or vice versa.
I hope it helps!
Answer:
3- is the charge and 8 dots on its Lewis dot structure.
Explanation:
Hello there!
In this case, since nitrogen is an element with five valence electrons (electrons on its outer shell), we infer that it needs three bonds to complete the octet, for which its charge, when forming nitride ions is 3-, which means it has received three electrons. Thus, when drawing the Lewis dot structure, it is evident that is will have 5+3 = 8 dots due to the electron reception.
Regards!
Acetylene is the only fuel gas suitable for gas welding because of its favourable flame characteristics of both high temperature and high propagation rates. Other fuel gases, such as propane, propylene or natural gas, produce insufficient heat input for welding but are used for cutting, torch brazing and soldering.
Answer:
0.007756M KHP; 0.0009695 moles NaOH reacts; 0.03488M NaOH.
Explanation:
Potassium hydrogen phthalate, KHP, is a salt used as standard to determine concentration of basic solutions as NaOH solutions.
To find molarity of the KHP solution we need to convert mass of KHP to moles and divide this in 125mL = 0.125L:
<em>Moles KHP -Molar mass: 204.22g/mol-:</em>
0.198g * (1mol / 204.22g) = 0.0009695 moles KHP
<em>Molarity:</em>
0.0009695 moles KHP / 0.125L = 0.007756M KHP
NaOH reacts with KHP as follows:
NaOH + KHP → Na⁺ + KP⁻ + H₂O
That means 1 mole of NaOH reacts per mole of KHP, that means moles of NaOH that reacts are = Moles of KHP added:
0.0009695 moles NaOH reacts
In 27.80mL = 0.02780L the NaOH was contained. Molarity is:
0.0009695 moles NaOH / 0.02780L =
0.03488M NaOH
