Answer:
7,94 minutes
Explanation:
If the descomposition of HBr(gr) into elemental species have a rate constant, then this reaction belongs to a zero-order reaction kinetics, where the r<em>eaction rate does not depend on the concentration of the reactants. </em>
For the zero-order reactions, concentration-time equation can be written as follows:
[A] = - Kt + [Ao]
where:
- [A]: concentration of the reactant A at the <em>t </em>time,
- [A]o: initial concentration of the reactant A,
- K: rate constant,
- t: elapsed time of the reaction
<u>To solve the problem, we just replace our data in the concentration-time equation, and we clear the value of t.</u>
Data:
K = 4.2 ×10−3atm/s,
[A]o=[HBr]o= 2 atm,
[A]=[HBr]=0 atm (all HBr(g) is gone)
<em>We clear the incognita :</em>
[A] = - Kt + [Ao]............. Kt = [Ao] - [A]
t = ([Ao] - [A])/K
<em>We replace the numerical values:</em>
t = (2 atm - 0 atm)/4.2 ×10−3atm/s = 476,19 s = 7,94 minutes
So, we need 7,94 minutes to achieve complete conversion into elements ([HBr]=0).
Answer:
P=12.16 atm
Explanation:
Using the formula of ideal gas law:
PV = nRT
P= nRT/V
n= number of moles
R= Avogadro constant = 0.0821
T= Temperature in K => ºC + 273.15 K
P= (1.50 moles)(0.0821)( 296.15 K)/ 3.00L
P= 12.15
Explanation:
According to the Handerson equation,
pH = 
or, pH =
Putting the given values into the above equation as follows.
pH =
5.0 = 6.0 + log \frac{\text{conjugate base}}{\text{acid}}[/tex]
= -1.0
or, 
= 0.1
Therefore, we can conclude that molar ratios of conjugate base to weak acid for given solution is 0.1.
Answer:
100 mL
Explanation:
The reaction that takes place is:
- CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂
First we <u>convert 500 mg of CaCO₃ into mmoles</u>, using its <em>molar mass</em>:
- 500 mg ÷ 100 mg/mmol = 5 mmol CaCO₃
Then we <u>convert 5 mmoles of CaCO₃ into HCl mmoles</u>, using the <em>stoichiometric coefficients of the balanced reaction</em>:
- 5 mmol CaCO₃ *
= 10 mmol HCl
Finally we <u>calculate the volume of a 0.10 M HCl solution (such as stomach acid) that would contain 10 mmoles</u>:
- 10 mmol / 0.10 M = 100 mL