All categories

3 years ago

Answer the following questions using the results of the following Unknown Solution Analysis:

Chemistry

1 answer:

STALIN [3.7K]3 years ago

6 0

Answer:

(a). strontium iodide.

(b). SrI2.

Explanation:

This question wants to test our knowledge on qualitative part of chemistry practical.

The first part is flame test which is a physical test. The flame test that was done on the com gave red flame.

Deduction: This confirms the presence of Strontium and Calcium.

The next thing is the chemical tests.

(1). Unknown + ammonium carbonate: gives white precipitate (ppt.).

Deduction: presence of Calcium and Strontium ions

(2). Unknown + Ammonium phosphate - white ppt.

Deduction: presence of Calcium and Strontium ions.

(3). Unknown sample + ammonium sulfate - white ppt.

Deduction: presence of Strontium ion confirmed.

(3). Halide test: purple hexane layer.

Deduction: shows the presence of Iodine.

Therefore, the final conclusion can be made as;

(a). The name of the chemical compound is strontium iodide.

(b). The chemical formula for the compound is SrI2.

You might be interested in

Determine the mole fractions and partial pressures of CO2, CH4, and He in a sample of gas that contains 1.20 moles of CO2, 1.79

BARSIC [14]

Answer : The mole fraction and partial pressure of $CH_4,CO_2$ and $He$ gases are, 0.267, 0.179, 0.554 and 1.54, 1.03 and 3.20 atm respectively.

Explanation : Given,

Moles of $CH_4$ = 1.79 mole

Moles of $CO_2$ = 1.20 mole

Moles of $He$ = 3.71 mole

Now we have to calculate the mole fraction of $CH_4,CO_2$ and $He$ gases.

$\text{Mole fraction of }CH_4=\frac{\text{Moles of }CH_4}{\text{Moles of }CH_4+\text{Moles of }CO_2+\text{Moles of }He}$

$\text{Mole fraction of }CH_4=\frac{1.79}{1.79+1.20+3.71}=0.267$

and,

$\text{Mole fraction of }CO_2=\frac{\text{Moles of }CO_2}{\text{Moles of }CH_4+\text{Moles of }CO_2+\text{Moles of }He}$

$\text{Mole fraction of }CO_2=\frac{1.20}{1.79+1.20+3.71}=0.179$

and,

$\text{Mole fraction of }He=\frac{\text{Moles of }He}{\text{Moles of }CH_4+\text{Moles of }CO_2+\text{Moles of }He}$

$\text{Mole fraction of }He=\frac{3.71}{1.79+1.20+3.71}=0.554$

Thus, the mole fraction of $CH_4,CO_2$ and $He$ gases are, 0.267, 0.179 and 0.554 respectively.

Now we have to calculate the partial pressure of $CH_4,CO_2$ and $He$ gases.

According to the Raoult's law,

$p_i=X_i\times p_T$

where,

$p_i$ = partial pressure of gas

$p_T$ = total pressure of gas = 5.78 atm

$X_i$ = mole fraction of gas

$p_{CH_4}=X_{CH_4}\times p_T$

$p_{CH_4}=0.267\times 5.78atm=1.54atm$

and,

$p_{CO_2}=X_{CO_2}\times p_T$

$p_{CO_2}=0.179\times 5.78atm=1.03atm$

and,

$p_{He}=X_{He}\times p_T$

$p_{He}=0.554\times 5.78atm=3.20atm$

Thus, the partial pressure of $CH_4,CO_2$ and $He$ gases are, 1.54, 1.03 and 3.20 atm respectively.

4 0

3 years ago

The electrolyte of the following is:

ozzi

An electrolyte is a term used to describe a compound that can dissociate into ions as it is nothing but an ionic compound, a salt made up of a positively charged cation and negatively charged anion.

Here the correct answer is D. Since there are no hydrocarbons or any other organic compound, that do not possess partial let alone full charges, all of them can dissociate in solution to give their ions.

This allows for the solution to be able to conduct electricity.

4 0

3 years ago

What kind of chemical change involves breaking down substances using electricity?

Vesnalui [34]

The chemical change that involves breaking down substances using electricity is C. Electrolysis.

8 0

3 years ago

Read 2 more answers

The change in entropy, ΔS∘rxn , is related to the the change in the number of moles of gas molecules, Δngas . Determine the chan

kifflom [539]

Explanation:

Entropy of a reaction ΔS∘rxn is the degree of disoderliness in a system. Gases generally have a higher degree of disorder compared to liquids. Hence for the reaction 2H2(g)+O2(g) ⟶ 2H2O(l), the entropy decreases sice the reactants are in the gaseous state and the products is in the liquid state of matter

4 0

3 years ago

Use what you know about phase changes, mixtures, and chemical reactions to answer the following questions.

saveliy_v [14]

Answer:

D- beaking bread

Explanation:

The trapped carbon dioxide makes the dough rise, and the alcohol evaporates during the baking process this is an irreversible chemical change.

5 0

3 years ago