Answer:
6.25 μg/mL
Explanation:
When a dilution is made, the mass of the solute is conserved (Lavoiser's law), so the mass pipetted will be the mass in the assay. The mass is the concentration (C) multiplied by the volume (V). If the pipet solution is called 1, and the assay 2:
m1 = m2
C1*V1 = C2*V2
C1 = 250 μg/mL
V1 = 25 μL
V2 = 975 μL + 25 μL = 1000 μL (is the final volume of the assay after the addition of LDH)
250*25 = C2*1000
C2 = 6.25 μg/mL
POH value was calculated by the negative logarithm of hydroxide ion concentration.
To know the hydrogen ion concentration, we need to know the pH value, that can be found out if pOH is known
pH + pOH = 14
pH = 14 - pOH
pH = 10.65
once the pH is known we have to find the antilog.
[H⁺] = antilog (-pH)
antilog can be found by
[H⁺] = 10^(-10.65)
[H⁺] = 2.2 x 10⁻¹¹ M
Answer:
<u><em></em></u>
- <u><em>máquina simple: palanca</em></u>
Explanation:
En vista de que la pregunta está realizada en español, la respuesta la doy en el mismo lenguage.
La<em> palanca</em> es una máquina simple que consiste en una barra rígida que puede girar alrededor the un punto the pivote.
La forma en que functiona una palanca es que se aplica la ferza en el extremo de la barra que está más alejado del pivote. Este extremo puede desplazarse una larga distancia o arco, con una fuerza pequeña, haciendo que los puntos que están al otro lado del pivote, a una menor distancia de este, se desplacen una distancia o arco menor pero con más fuerza que la aplicada.
Answer: D
Explanation:
I assume you meant 
.
- The atomic mass of potassium is 39.0983 g/mol.
- The atomic mass of sulfur is 32.065 g/mol.
- The atomic mass of oxygen is 15.9994 g/mol.
So, the formula mass of potassium sulfate is 2(39.0983)+32.065+4(15.9994)=174.2592 g/mol.
So, 5.00 moles have a mass of (5.00)(174.2592), which is about <u>870 g</u>
