Answer:
pH = 4.27. Porcentaje de disociación: 0.03%
Explanation:
El pH de un ácido débil, HX, se obtiene haciendo uso de su equilibrio:
HX(aq) ⇄ H⁺(aq) + X⁻(aq)
Donde la constante de equilibrio, Ka, es
Ka = 1.65x10⁻⁸ = [H⁺] [X⁻] / [HX]
Como los iones H⁺ y X⁻ vienen del mismo equilibrio podemos decir:
[H⁺] = [X⁻]
[HX] es:
20g * (1mol/55g) = 0.3636moles / 2.100L = 0.1732M
Reemplazando es Ka:
1.65x10⁻⁸ = [H⁺] [H⁺] / [0.1732M]
2.858x10⁻⁹ = [H⁺]²
5.35x10⁻⁵M = [H⁺]
pH = -log[H⁺]
<h3>pH = 4.27</h3>
El porcentaje de disociacion es [X⁻] / [HX] inicial * 100
Reemplazando
5.35x10⁻⁵M / 0.1732M * 100
<h3>0.03%</h3>
Answer:
1.6g/mL
Explanation:
Density equation is D=m/v
Density = g/mL
m=mass of sample in grams
v = volume of sample in mL
The volume of a square can be calculated by V=l*w*h.
In this case it is 5cm*5cm*5cm = 125cm^3
Since we know that 1cm^3 ~ 1mL we can convert the volume to mL as so:
125cm^3 (1mL/(1cm^3)) = 125mL
Then simply plug into the density equation:
D=200g/125mL = 1.6g/mL
Answer:
3. The temperatures of the two substances equalize.
Explanation:
- As two objects at different temperatures are placed in contact, heat is transferred from the warmer to the cooler object until the temperature of the two objects be the same.
- The amount of heat that is transferred from the warmer object is equal to the amount of heat that is transferred into the cooler object.
- This is in agreement with the law of conservation of energy.
- <em>So, the right choice is: 3. The temperatures of the two substances equalize. </em>
<em></em>
Answer:
True statment
2) Styrofoam would make a good calorimeter
3) Insulating material would make a good calorimeter
Explanation:
The calorimeter is one which is insulated that is which will not absorb or let the heat to escape from it. the calorimeter is used to measure the heat change during a process so if it will allow to exchange heat with surrounding it will deviate the readings or observence.
Copper is a good conductor of heat so we cannot use it make a calorimeter.
Hence
1) Copper would make a good calorimeter : False
2) Styrofoam would make a good calorimeter: True
Styrofoam is a bad conductor or insulator so it can be and it is used for calorimeter.
3) Insulating material would make a good calorimeter
: True
4) A good calorimeter should easily absorb heat : false
Answer:
The second option
Explanation:
Speed is defined at the rate at which distance changes with time. It is scalar quantity and it is expressed as shown below:
Speed = 
At constant speed the rate of change of distance with time is the same. On the second graph, this is noticeable. Both distance and time change at the same rate.
