Answer:
1 ml
Explanation:
formula multiply the volume value by one
Photosynthesis (incl. water) is important for most plants.
Do a quick search on photosynthesis and you will get some good answers
Answer: The correct option is B.
Explanation: This is an example of radioactive decay and all the radioactive decay processes follow First order of kinetics.
Expression for the half life of first order kinetics is:
We are given:
Putting in above equation, we get:
Expression to calculate the amount of sample which is unchanged is:
where,
N = Amount left after time t
= Initial amount
k = Rate constant
t = time period
Putting value of k = 0.05625 and t = 24.6 in above equation, we get:
The above fraction is the amount of sample unchanged and that is equal to 
Hence, the correct option is B.
Answer:
8.09x10⁻⁵M of Fe³⁺
Explanation:
Using Lambert-Beer law, the absorbance of a sample is proportional to its concentration.
In the problem, the Fe³⁺ is reacting with KSCN to produce Fe(SCN)₃ -The red complex-
The concentration of Fe³⁺ in the reference sample is:
4.80x10⁻⁴M Fe³⁺ × (5.0mL / 50.0mL) = 4.80x10⁻⁵M Fe³⁺
<em>Because reference sample was diluted from 5.0mL to 50.0mL.</em>
<em>That means a solution of 4.80x10⁻⁵M Fe³⁺ gives an absorbance of 0.512</em>
Now, as the sample of the lake gives an absorbance of 0.345, its concentration is:
0.345 × (4.80x10⁻⁵M Fe³⁺ / 0.512) = <em>3.23x10⁻⁵M. </em>
As the solution was diluted from 20.0mL to 50.0mL, the concentration of Fe³⁺ in Jordan lake is:
3.23x10⁻⁵M Fe³⁺ × (50.0mL / 20.0mL) = <em>8.09x10⁻⁵M of Fe³⁺</em>
