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ludmilkaskok [199]
3 years ago
13

How many microliters of original sample are required to produce a final dilution of 10-2 in a total volume of 0.2 mL? 1 microlit

er is 10-6 L or 10-3 mL.
Chemistry
1 answer:
Kisachek [45]3 years ago
3 0

Answer:

The required volume of the original sample required is 2 micro liter

Explanation:

assuming the original sample concentration is 1N

after  final dilution of 10-2 solution concentration becomes 0.01 N

normality of original sample  = 1 N

normality  of final solution = 0.01 N

volume of  original sample= ?

volume of   final solution  = 0.2 mL

Considering thef formula below :

N1V1 = N2V2

V1 = (N2V2)/N1

= (0.01*0.2)/1

= 0.002 mL

1 milli liter = 1000 micro liter

0.002 mL = 2 micro liter

The original sample required is 2 micro liter

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Answer:

Las siguientes son reacciones químicas;

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Explanation:

Una reacción química da como resultado la formación de una (s) sustancia (s) nueva (s), mientras que un cambio físico no conduce a la formación de una sustancia nueva.

Las siguientes son reacciones químicas;

combustión de leña: la combustión de madera implica la oxidación del carbono según la reacción; C (s) + O2 (g) -------> CO2 (g)

oxidación del hierro: La oxidación del hierro conduce a la formación de óxidos de hierro. Como; 2Fe (s) + O2 (g) ----> 2FeO (s)

descomposición del agua en hidrógeno y oxígeno: esta es una reacción química en la que el agua se descompone de la siguiente manera; 2H2O (l) -----> 2H2 (g) + O2 (g)

Todos estos procesos enumerados anteriormente conducen a la formación de nuevas sustancias, por lo tanto, son reacciones químicas.

3 0
2 years ago
1. Show that heat flows spontaneously from high temperature to low temperature in any isolated system (hint: use entropy change
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Answer:

1 ) Δs ( entropy change for hot block ) = - Q / th  ( -ve shows heat lost to cold block )

Δs ( entropy change for cold block ) = Q / tc

∴ Total Δs = ΔSc + ΔSh

                 = Q/tc - Q/th

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Explanation:

<u>1) To show that heat flows spontaneously from high temperature to low temperature </u>

example :

Pick two(2) solid metal blocks with varying temperatures ( i.e. one solid block is hot and the other solid block is cold )

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8 0
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