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2 years ago

Question 20 (Essay Worth 8 points)

Chemistry

2 answers:

sleet_krkn [62]2 years ago

8 0

Answer: The correct answer is c

Explanation: its is the right answer

KIM [24]2 years ago

4 0

Answer:

See explanation

Explanation:

FeCl3 +3 NaOH →3 NaCl + Fe(OH)3

One mole of ferric chloride reacts with three moles of sodium hydroxide to yield three moles of sodium chloride and one mole of ferric hydroxide. The reaction demonstrate the law of conservation of mass because the total mass of reactants equals the total masses of products formed.

b) neutralization reaction

c) lead is lower than zinc in the activity series of metals but calcium is higher than zinc hence zinc cannot displace calcium but it can displace lead.

d) the half life is 21 hours

e) it will take 320g grams 21 hours to remain 160g

It will take 160g 42 hours to remain 80g

It will take 80g 63 hours to remain 40g

It will take 40g 84 hours to remain 20g

It will take 20g 105 hours to remain 10g

It will take 10g 126 hours to remain 5g

It will take 5g 147 hours to remain 2.5g

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The four rows of data below show the boiling points for a solution with no solute, sucrose (C12H22O11), sodium chloride (NaCl),

choli [55]

Answer:

The four rows of data below show the boiling points for a solution with no solute, sucrose (C12H22O11), sodium chloride (NaCl), and calcium chloride (CaCl2) (not in that order). Which boiling point corresponds to calcium chloride?

A. 101.53° C

B. 100.00° C

C. 101.02° C

D. 100.51° C

Which of the following solutions will have the lowest freezing point?

A. 1.0 mol/kg sucrose (C12H22O11)

B. 1.0 mol/kg lithium chloride (LiCl)

C. 1.0 mol/kg sodium phosphide (Na3P)

D. 1.0 mol/kg magnesium fluoride (MgF2)

Which of the following compounds will be most effective in melting the ice on the roads when the air temperature is below zero?

A. sodium iodide (NaI)

B. magnesium sulfate (MgSO4)

C. potassium bromide (KBr)

D. All will be equally effective.

Four different solutions have the following vapor pressures at 100°C. Which solution will have the greatest boiling point?

A. 98.7 kPa

B. 96.3 kPa

C. 101.3 kPa

D. 100.2 kPa

Four different solutions have the following boiling points. Which boiling point corresponds to a solution with the lowest freezing point?

A. 101.2°C

B. 105.9°C

C. 102.7°C

D. 108.1°C

Explanation:

The following are the answers to the different questions:

A. 101.53° C

Which of the following solutions will have the lowest freezing point?

D. 1.0 mol/kg magnesium fluoride (MgF2)

Which of the following compounds will be most effective in melting the ice on the roads when the air temperature is below zero?

A. sodium iodide (NaI)

Four different solutions have the following vapor pressures at 100°C. Which solution will have the greatest boiling point?

B. 96.3 kPa

Four different solutions have the following boiling points. Which boiling point corresponds to a solution with the lowest freezing point?

D. 108.1°C

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2 years ago

How much energy is required to heat 0.24 KG lutetium from 296.2K to 373.5 K? The specific heat for lutetium is 0.154 J/g-K

Olenka [21]

I’m not sure I need help with this question

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2 years ago

C2H5OH(aq) + MnO− 4 (aq) → Mn2+(aq) + CH3COOH(aq) of acetic acid from ethanol by the action of permanganate ion in acidic soluti

Andreas93 [3]

Answer :

Ethanol $(C_2H_5OH)$ act as reducing agent.

The smallest possible integer coefficient of $MnO_4^-$ in the combined balanced equation is, 4

Explanation :

Redox reaction or Oxidation-reduction reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.

Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. In this, oxidation state of an element increases. Or we can say that in oxidation, the loss of electrons takes place.

Reduction reaction : It is defined as the reaction in which a substance gains electrons. In this, oxidation state of an element decreases. Or we can say that in reduction, the gain of electrons takes place.

Reducing agent : It is defined as the agent which helps the other substance to reduce and itself gets oxidized. Thus, it will undergo oxidation reaction.

Oxidizing agent : It is defined as the agent which helps the other substance to oxidize and itself gets reduced. Thus, it will undergo reduction reaction.

The given chemical reaction is,

$C_2H_5OH(aq)+MnO_4^-(aq)\rightarrow CH_3COOH(aq)+Mn^{2+}(aq)$

The oxidation-reduction half reaction will be :

Oxidation : $C_2H_6O\rightarrow C_2H_4O_2$

Reduction : $MnO_4^-\rightarrow Mn^{2+}$

Now balance oxygen atom on both side.

Oxidation : $C_2H_6O+H_2O\rightarrow C_2H_4O_2$

Reduction : $MnO_4^-\rightarrow Mn^{2+}+4H_2O$

Now balance hydrogen atom on both side.

Oxidation : $C_2H_6O+H_2O\rightarrow C_2H_4O_2+4H^+$

Reduction : $MnO_4^-+8H^+\rightarrow Mn^{2+}+4H_2O$

Now balance the charge.

Oxidation : $C_2H_6O+H_2O\rightarrow C_2H_4O_2+4H^++4e^-$

Reduction : $MnO_4^-+8H^++5e^-\rightarrow Mn^{2+}+4H_2O$

In order to balance the electrons, we multiply the oxidation reaction by 5 and reduction reaction by 4 and then added both equation, we get the balanced redox reaction.

Oxidation : $5C_2H_6O+5H_2O\rightarrow 5C_2H_4O_2+20H^++20e^-$