In a flame photometric analysis, salt solution is first vaporized using the heat of flame, followed by this electrons from valance shell gets excited from ground state to excited state. Followed by this de-excitation of electron bring backs electrons to ground state. This process is accompanied by emission of photon. The photon emitted is characteristic of an element, and number of photons emitted can be used for quantitative analysis.
<span>Following are the investigative question that you can answer by doing this experiment.
</span>1) What information can be obtained from the colour of flame?
2) <span>State the relationship between wavelength, frequency, and energy?
</span><span>3) Can you identify the metal present in unknown sample provided?
4) How will you identify amount of metal present in sample solution?
5) </span><span>Why do different chemicals emit light of different colour?</span><span>
</span>
Answer:
The correct answers are:
"Only about 3 percent of Earth's water is fresh water."
"About 75% percent of the fresh water on Earth is frozen in ice sheets."
"The largest source of usable fresh water is groundwater."
Explanation:
3 percent of Earth's water is most certainly fresh water. Confirmed with a few fact checks.
The largest source of usable fresh water on Earth is groundwater. It's more difficult to access but it's there and much more usable than water say frozen in ice on the sea.
The most correct option left would be 75% of Earth's freshwater being in ice sheets even though it's about 70%.
Answer:
2.47L
Explanation:
Using the combined gas law equation as follows:
P1V1/T1= P2V2/T2
Where;
P1 = initial pressure (mmHg)
P2 = final pressure (mmHg)
V1 = initial volume (L)
V2 = final volume (L)
T1 = initial temperature (K)
T2 = final temperature (K)
According to the information provided in this question;
P1 = 705mmHg
P2 = 760mmHg (STP)
V1 = 3.00L
V2 = ?
T1 = 35°C = 35 + 273 = 308K
T2 = 273K (STP)
Using P1V1/T1= P2V2/T2
705 × 3/308 = 760 × V2/273
2115/308 = 760V2/273
Cross multiply
308 × 760V2 = 2115 × 273
234,080V2 = 577,395
V2 = 577,395 ÷ 234,080
V2 = 2.47L