Answer:
In the third tube, the concentration is 0.16 ug/mL
Explanation:
In the first step, the solution is diluted by 5. Then, the concentration will be
20 ug/mL / 5 = 4 ug/mL
Then, in the second step this 4 ug / ml solution is diluted by a factor of five again:
4 ug /ml / 5 = 0.8 ug/mL
This solution is then diluted again by 5 and the concentration in the third tube will be then:
0.8 ug/mL / 5 = <u>0.16 ug/mL </u>
<u />
Another way to calculate this is to divide the original concentration by the dilution factor ( 5 in this case) elevated to the number of dilutions. In this case:
Concentration in the third tube = 20 ug/mL / 5³ = 0.16 ug/mL
Answer:
<h2>250 cm³</h2>
Explanation:
The volume of a substance when given the density and mass can be found by using the formula
From the question we have
Wr have the final answer as
<h3>250 cm³</h3>
Hope this helps you
Net overall dissociation:
Na2CO3 ---> 2Na(-) + CO3(2-)
*The ion charge is in parenthesis
Answer:
Average atomic mass of E = 103.57 amu
Explanation:
Given data:
Average atomic mass of E = ?
Abundance of E-102.658 = 56.67%
Abundance of E-104.770 = 43.33%
Solution:
Average atomic mass of E = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass of E = (56.67×102.658)+(43.33×104.770) /100
Average atomic mass of E = 5817.63 + 4539.68 / 100
Average atomic mass of E = 10357.31 / 100
Average atomic mass of E = 103.57 amu.
