Answer:
The wavelength the student should use is 700 nm.
Explanation:
Attached below you can find the diagram I found for this question elsewhere.
Because the idea is to minimize the interference of the Co⁺²(aq) species, we should <u>choose a wavelength in which its absorbance is minimum</u>.
At 400 nm Co⁺²(aq) shows no absorbance, however neither does Cu⁺²(aq). While at 700 nm Co⁺²(aq) shows no absorbance and Cu⁺²(aq) does.
The Lewis structure of PF3 shows that the central phosphorus atom has one non bonding and three bonding electron pairs. In this compound each Phosphorus atom contributes 5 valence electrons while each fluoride contributes 7 valence electrons making a total of 26 valence electrons. The central Phosphorus atom forms single bonds with each of the fluoride atoms. Phosphorus, therefore ends up with a non-bonding pair since the fluoride atoms already have 8 electrons around them. <span />
<u>We are given:</u>
Initial Temperature = 90°c
Final Temperature = 120°c
Heat applied(ΔH) = 500 Joules
Specific heat(c) = 0.9 Joules / g°C
Mass of Aluminium(m) = ?
<u>Change in temperature:</u>
ΔT = Final temp. - Inital Temp.
ΔT = 120 - 90
ΔT = 30°c
<u>Calculating the mass:</u>
We know the formula:
ΔH = mcΔT
replacing the values:
500 = m(0.9)(30)
500 = m(27)
m = 500/27
m = 18.52 grams
Answer:
I DID HOW I KNOW . I HOPE IT WILL HELP YOU :D
I think the best answer is b): it contains particles that can settle out.
The definition of suspension is a heterogeneous (that is same in all parts) mixture that contains particles that could undergo sedimentation (settle down) - this definition is close to b). It should not matter whether those particles are nutrients( so A or C are not good answers).
