1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
11Alexandr11 [23.1K]
3 years ago
9

A solution contains some or all of the ions Cu2+,Al3+, K+,Ca2+, Ba2+,Pb2+, and NH4+. The following tests were performed, in orde

r, on the solution.1. Addition of 6 M HCl produced no reaction.2. Addition of H2S with 0.2 M HCl produced a black solid.3. Addition of (NH4)2S produced a white solid.4. Addition of (NH4)2HPO4 in NH3 produced no reaction.5. The final supernatant when heated produced a purple flame.Identify which of these ions were present in the solution (P), which were absent (A), and which were inconclusive (I)a. Cu2+b. Al3+c. K+d. Ca2+e. Ba2+f. Pb2+g. NH4+
Chemistry
1 answer:
xeze [42]3 years ago
6 0

Answer:

See below explanation

Explanation:

When having a mixture of metals in solution, you may perform an analytical study (using selective chemical conditions), that may help you to determine whether a metal (cation) is present or not

Using selective analytes (or conditions), leads to consecutive precipitations, until most of the cations are separated in precipitates

With this technique, you may identify metals in different groups, each group will have its analyte (or condition), which will help to have a different precipitate:

- Group I: Ag⁺, Pb⁺², Hg⁺²;  Analyte: HCL ; Precipitate: AgCl (white) , PbCl₂, HgCl₂

- Group II: As⁺³ , Bi⁺³, Cd⁺², Cu⁺² , Sb⁺³, Sn⁺² ; Analyte: H₂S (g) with HCL ; Precipitate: As₂S₃ , Bi₂S₃ , CdS (yellow) , CuS (black), Sb₂S₃, SnS

- Group III: Co⁺², Fe⁺², Fe⁺³, Mn⁺², Ni⁺², Zn⁺², Al⁺³, Cr⁺³; Analyte: NaOH or NH₃ with (NH₄)₂S (ac) ; Precipitate: CoS (black) , FeS, MnS , NiS (black), ZnS (white) , Al(OH)₃ (white), Cr(OH)₃  

- Group IV: Mg⁺², Ca⁺², Sr⁺², Ba⁺²; Analyte: Na₂CO₃ (ac) or (NH₄)₂HPO₄ (ac); Precipitate: respective carbonate or phosphate MgCO₃/MgHPO₄, CaCO₃/CaHPO₄ , SrCO₃/SrHPO₄, BaCO₃/BaHPO₄

- Group V: Li⁺, K⁺, Na⁺, Rb⁺, Cs⁺, NH₄⁺ ; will remain all in final solution

According to the original statement:

A solution contains one or more of the following: Cu⁺², Al⁺³, K⁺, Ca⁺², Ba⁺², Pb⁺², NH₄⁺

1) Addition on HCl 6M produces no change: we can say the sample does not contain Pb⁺² (group I)

2) Addition of H₂S with 0.2 M HCL produced a black solid: we could say sample contains Cu⁺²(group II)

3) Addition of (NH₄)₂HPO₄ in NH₃ produces no reaction: we could say we don´t have Ca⁺² and /or Ba⁺²  (group IV)

4) The final supernatant, when heated produced a purple flame: in the final solution, we have K⁺ (group V), which produces a purple flame (based on its characteristic emission spectrum when subjected to flame)

This analysis will be inconclusive for NH₄⁺ (according to above describe technique)

You might be interested in
What is the partial pressure of 0.50 mol Ne gas combined with 1.20 mol Kr gas at a final pressure of 730 torr?
WARRIOR [948]
  The partial pressure  of 0.50  Ne  gas    is   214.71  torr


      calculation

 the partial   pressure  of Ne  = moles  of Ne/total moles  x  final  pressure

 
find  the total  moles  of the air mixture  

that is moles of   Ne  +  moles of K=  0.50 + 1.20  =  1.70 moles
  

The partial  pressure  is therefore =   0.50 /1.70  x  730  =  214.71  torr
   
8 0
3 years ago
Read 2 more answers
Name the postulates of Dalton atomic theory​
Elis [28]

Answer:

All matter consists of indivisible particles called atoms. Atoms of the same element are similar in shape and mass, but differ from the atoms of other elements. Atoms cannot be created or destroyed. Atoms of different elements may combine with each other in a fixed, simple, whole number ratios to form compound atoms.

Explanation:

Hope this helps have a great day

8 0
3 years ago
What type of compound is almost always found as a solid?
Evgesh-ka [11]
Hi , your answer is Ionic.
4 0
3 years ago
Read 2 more answers
E
Nana76 [90]
Hey :)

Air pollution

Hope this helps!

Good luck in your test :)
7 0
3 years ago
Read 2 more answers
While waiting for your car to warm up one winter morning, you notice a liquid dripping from your tailpipe. You recently
tangare [24]

Answer:

A

Explanation:

Menthol (M 156.3 g/mol), the strong-smelling substance in many cough drops, is a compound of carbon, hydrogen, and oxygen. When 0.1595 g of menthol was bunted in a combustion apparatus. 0.449 g of CO_2 and 0.184 g of H_2 O formed.

3 0
3 years ago
Other questions:
  • About _% of high school seniors report misusing prescription
    11·1 answer
  • For the following reaction, 11.6 grams of sulfur are allowed to react with 23.5 grams of carbon monoxide . sulfur(s) + carbon mo
    15·1 answer
  • When is an isotope considered stable?<br> (Select all that apply.)
    6·1 answer
  • Given the starting solution had a concentration of 1.25 m, how many moles of co[h2o]6cl2 were available in the amount of startin
    6·1 answer
  • Convert 205 L to ul.
    6·2 answers
  • A mixture of He, Ne, and N2 gases are a pressure of 1.348. If the pressures of He and Ne are 0.124 atm, what is the partial pres
    8·2 answers
  • How can chemical weathering make it easier for mechanical weathering to occur ? MY EXAMS!!!
    13·1 answer
  • How many neutrons are present in 1 atom of chlorine?
    8·2 answers
  • Draw the expanded structural formula for the condensed formula (CH3)2CHCH2OCH2CH3 . Draw all hydrogen atoms
    11·1 answer
  • Determine the difference between archaea and bacteria. (1 point)
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!