Answer:
10 km/hr
Explanation:
We are told that a jogger runs;
3km in 0.3 hr and
7 km in 0.7 hr
We are required to determine the average speed;
We need to know that average speed is given by;
Average speed = Total distance ÷ total time
In this case;
Total distance = 10 km ( 3km + 7 km)
Total time = 0.3 hr + 0.7 hr
= 1 hr
Thus;
Average speed = 10 km ÷ 1 hr
= 10 km/hr
Therefore, the average speed of the jogger is 10 km/hr
Correct answer :
C.) Radiation
Because potassium is more reactive than hydrogen
Answer:
La densidad experimenta una disminución
Explanation:
Hola!
En este caso, debemos recordar que la adición de agua incrementa el volumen donde se encuentra un soluto disuelto, el cual posee una cantidad de materia constante. De este modo, sabiendo que la densidad es:
Al incrementar el denominador (volumen), la densidad experimenta una disminución, al estar en relación inversamente proporcional.
Muchos saludos!
A 0.50 M solution of a monoprotic acid HA with a pH of 2.24 would be, first, a weak acid, as it does not dissociate fully. This leaves us with an equilibrium expression: HA (aq) <span>⇌ H+ (aq) + A- (aq)
Where A- is the conjugate base of the weak acid.
In a study of equilibrium, we remember that the ka value is the acid dissociation constant, and has the equation:
Ka = (concentration of H+)(concentration of conjugate base)/concentration of acid
We know the concentration of H+ and A- are 10^-2.24 by the definition of a pH being the -log(concentration of H+).
The concentration of the acid has gone down a little bit, as it has partially dissociated into H+ and A-, so we'll have to subtract 10^-2.24 from 0.50 for the concentration of the acid to account for the dissociation.
The final equation would then become:
[H+]*[A-]/[HA] = Ka
(10^-2.24) * (10^-2.24) / (0.50 - 10^-2.24) = Ka
(3.31 * 10^-5) / (0.494) = Ka
Ka = 6.70 * 10^-5</span>