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2 years ago

8

A soda ash is analyzed in the analytical chemistry laboratory by titration with standard hydrochloric acid. The analysis is perf

ormed in triplicate with the following results: 93.50, 93.58, 93.43% Na2CO3. Within what range are you 95% confident that the true value lies?

1 answer:

Gre4nikov [31]2 years ago

6 0

Answer:

93.50±5%

Explanation:

Hello,

The average of the results turns out in 93.50% Na2CO3, thus, the range that the true value lies on is:

93.50±5%

For us to have be 95% confident that we've got the correct result.

Best regards.

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The enthalpy change for the explosion of ammonium nitrate with fuel oil is –7198 kJ for every 3 moles of NH4NO3. What is the ent

anastassius [24]

Answer:

−2399.33 kJ

Explanation:

If NH₄NO₃ reacts with fuel oil to give a ΔH of -7198 for every 3 moles of NH₄NO₃

What is the enthalpy change for 1.0 mole of NH₄NO₃ in this reaction

∴ For every 1 mole, we will have $\frac{1}{3}$ of the total enthaply of the 3 moles

so, to determine the 1 mole; we have:

$\frac{1}{3}*(-7198kJ)$

= −2399.33 kJ

∴ the enthalpy change for 1.0 mole of NH₄NO₃ in this reaction = −2399.33 kJ

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2 years ago

Describe the process used to measure out a specific mass of a solid

Svetlanka [38]

Although the process varies slightly from one material to another, the general process is as follows:

1) Choose an appropriate container for the solid. This may be a petri dish or a beaker in which you want to prepare the solution of the solid or any other lab equipment.

2) Place the container on a mass balance, then turn the balance on. The mass balance will automatically zero-out the mass of the container, so that any mass that you add on the container will be the mass of the solid. Alternatively, you may first measure the mass of the empty container alone.

3) Add the solid using a lab spatula. The solid should be added more slowly when the reading on the scale comes close to the desired value.

4) Remove the container from the mass balance after the desired amount of solid has been added.

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2 years ago

Which is stronger, the strong force (SF) or the electromagnetic force (EMF)? Describe how they battle each other in the nucleus.

Roman55 [17]

Answer:uclear Force that holds together the nucleus of an atom. electromagnetic force. ... They are unstable because the Strong Force that would hold them together if the protons and neutrons were closer is weakened because the protons and neutrons get too far apart.

Explanation:

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2 years ago

For each of the following compounds, state whether it is ionic or covalent, and if it is ionic, write the symbols for the ions i

kupik [55]

Answer :

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The covalent compound are usually formed when two non-metals react.

Ionic compound : It is defined as the compound which is formed when electron gets transferred from one atom to another atom.

All the polyatomic ions always form an ionic compound.

Polyatomic ions : It is a charged species that composed of two or more atoms and these charged species are bonded by the covalent bond.

For the given options:

Option A: $KClO_4$

This compound is formed by the combination of potassium, $K^+$ which is a metal and $ClO_4^-$ ion which is a polyatomic ion. Thus, it will form an ionic compound.

Option B: $Mg(C_2H_3O_2)_2$

This compound is formed by the combination of magnesium, $Mg^{2+}$ which is a metal and $C_2H_3O_2^{-}$ ion which is a polyatomic ion. Thus, it will form an ionic compound.

Option C: $H_2S$

Hydrogen and sulfur, both are non-metals and they will form a covalent compound.

Option D: $Ag_2S$

This compound is formed by the combination of silver, $Ag^{+}$ which is a metal and sulfur, $S^{2-}$ which is a non-metal. Thus, it will form an ionic compound.

Option E: $N_2Cl_4$

Nitrogen and chlorine, both are non-metals and they will form a covalent compound.

Option F: $Co(NO_3)_2$

This compound is formed by the combination of cobalt, $Co^{2+}$ which is a metal and $NO_3^{-}$ ion which is a polyatomic ion. Thus, it will form an ionic compound.

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2 years ago

How much volume (in cm3) is gained by a person who gains 11.1 lbs of pure fat?

kirill [66]

The density of human fat is $0.918 g/cm^{3}$ . The mass of the pure fat is 11.1 lbs.

First convert mass from lb to g as follows:

1 lb=453.592 g

Thus,

$11.1 lb\rightarrow 11.1\times 453.592 g=5034.875 g$

Density of a substance is defined as mass per unit volume, thus volume can be calculated as:

$V=\frac{m}{d}$

Putting the values,

$V=\frac{5034.875 g}{0.918 g/cm^{3}}=5484.61 cm^{3}$

Therefore, volume gained by person will be $5484.61 cm^{3}$ .

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2 years ago