The answer is Ka = 1.00x10^-10.
Solution:
When given the pH value of the solution equal to 11, we can compute for pOH as
pOH = 14 - pH = 14 - 11.00 = 3.00
We solve for the concentration of OH- using the equation
[OH-] = 10^-pOH = 10^-3 = x
Considering the sodium salt NaA in water, we have the equation
NaA → Na+ + A-
hence, [A-] = 0.0100 M
Since HA is a weak acid, then A- must be the conjugate base and we can set up an ICE table for the reaction
A- + H2O ⇌ HA + OH-
Initial 0.0100 0 0
Change -x +x +x
Equilibrium 0.0100-x x x
We can now calculate the Kb for A-:
Kb = [HA][OH-] / [A-]
= x<span>²</span> / 0.0100-x
Approximating that x is negligible compared to 0.0100 simplifies the equation to
Kb = (10^-3)² / 0.0100 = 0.000100 = 1.00x10^-4
We can finally calculate the Ka for HA from the Kb, since we know that Kw = Ka*Kb = 1.0 x 10^-14:
Ka = Kw / Kb
= 1.00x10^-14 / 1.00x10^-4
= 1.00x10^-10
Answer:
D) N2O5
Explanation:
The molar mass of a substance is defined as the mass of this substance in 1 mol. To solve this question we must find the molar mass of each option:
<em>Molar mass NO:</em>
1N = 14g/mol*1
1O = 16g/mol*1
14+16 = 30g/mol
<em>Molar mass NO2:</em>
1N = 14g/mol*1
2O = 16g/mol*2
14+32 = 46g/mol
<em>Molar mass N2O:</em>
2N = 14g/mol*2
1O = 16g/mol*1
28+16 = 44g/mol
<em>Molar mass N2O5:</em>
2N = 14g/mol*2
5O = 16g/mol*5
28+80 = 108g/mol
That means the compound with the greatest mass is:
<h3>D) N2O5</h3>
Answer:
a. Zinc is the limiting reactant.
b. 
c. 
Explanation:
Hello there!
a. In this case, when zinc metal reacts with bromine, the following chemical reaction takes place:
Thus, since zinc and bromine react in a 1:1 mole ratio, we can compute their reacting moles to identify the limiting reactant:
Thus, since zinc has the fewest moles we infer it is the limiting reactant.
b. Here, we compute the grams of zinc bromide via both reactants:
That is why zinc is the limiting reactant, as it yields the fewest moles of zinc bromide product.
c. Here, since just 0.722 mol of bromine would react, we compute the corresponding mass:
Thus, the leftover of bromine is:
Best regards!
Answer:
Explanation:
Take out your periodic table.
The choices that have one 1 member of the periodic table on it are elements.
He is the symbol for Helium
O2 oxygen
C3 but this is really odd. It is Carbon but Carbon usually does not combine in 3s.
The rest are all compounds (they are made up of the elements on the periodic table). For example
H2SO4
is made up of 2 Hydrogens
1 sulfur
4 oxygens.
All the others do exactly the same thing.
