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2 years ago

Can someone plz help I also mark braniliest!

Chemistry

1 answer:

NNADVOKAT [17]2 years ago

6 0

Answer:

D. The chemical formula

Explanation:

For example, in the compound KCl, we know that there are two elements present because you can see it in the chemical formula. We know that KCl consists of potassium and chloride ions.

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Sasha placed a few objects one by one near a magnet. Only two of the objects Sasha placed moved toward the magnet. Which of the

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A galvanic cell consists of a Cu(s)|Cu2+(aq) half-cell and a Cd(s)|Cd2+(aq) half-cell connected by a salt bridge. Oxidation occu

Kryger [21]

Answer:

$Cd(s)|Cd^{2+}(aq) || Cu^{2+}(aq)|Cu(s)$

Explanation:

A galvanic cell is composed of two electrodes immersed in a suitable electrolyte and connected via a salt bridge. One of the electrodes serves as a cathode where reduction or gain of electrons takes place. The other half cell functions as an anode where oxidation or loss of electrons occurs.

The representation is given by writing the anode on left hand side followed by its ion with its molar concentration. It is followed by a salt bridge. Then the cathodic ion with its molar concentration is written and then the cathode.

As it is given that cadmium acts as anode, it must be on the left hand side and copper must be on right hand side.

$Cd(s)|Cd^{2+}(aq) || Cu^{2+}(aq)|Cu(s)$

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3 years ago

Ammonium nitrate is an ingredient in cold packs used by sports trainers for injured athletes. Calculate the change in temperatur

Ronch [10]

Answer:

See explanation

Explanation:

First, we need to use the correct expression:

Q = m*Cp*ΔT (1)

Q = n*ΔH (2)

These are the 2 expressions to calculate heat or energy.

Now, we want to know the change of temperature of the nitrate in water after being added, so with the innitial data of nitrate, we can calculate heat using the second expression. First, we need to calculate moles with the molecular mass:

n = m/MM

n = 42/80.1 = 0.52 moles

With these moles, we can calculate heat with the ΔH of this reaction:

Q = 0.52 * 25.7 = 13.364 kJ or 13,364 J

However, this heat as is being absorbed, the value would be negative.

Now that we have heat, we can use expression (1) and plug these values to solve for ΔT, but before, we need to know the total mass of the solution (water + nitrate)

m = 250 + 42 = 292 g

now, solving for ΔT:

-13,364 = 292 * 4.18 * ΔT

ΔT = -13,363 / (292 * 4.18)

ΔT = -10.95 °C

3 0

3 years ago

13. How many electrons are transferred in the following reaction? (The reaction is unbalanced.) Fe(s) + I'(aq) 12(s) + Fe3+(aq)

Nat2105 [25]

Answer : The correct option is, (C) 6

Explanation :

Oxidation-reduction reaction : It is a reaction in which oxidation and reduction reaction occur simultaneously.

Oxidation reaction : It is the reaction in which a substance looses its electrons. In this oxidation state increases.

Reduction reaction : It is the reaction in which a substance gains electrons. In this oxidation state decreases.

The given unbalanced chemical reaction is,

$Fe(s)+I^-(aq)\rightarrow I_2(s)+Fe^{3+}(aq)$

Half reactions of oxidation and reduction are :

Oxidation : $Fe(s)\rightarrow Fe^{3+}+3e^-$ ......(1)

Reduction : $2I^-(aq)+2e^-\rightarrow I_2$ .......(2)

In order to balance the electrons, we multiply equation 1 by 2 and equation 2 by 3, we get:

Oxidation : $2Fe(s)\rightarrow 2Fe^{3+}+6e^-$ ......(1)

Reduction : $6I^-(aq)+6e^-\rightarrow 3I_2$ .......(2)

The overall balanced chemical reaction will be:

$2Fe(s)+6I^-(aq)\rightarrow 3I_2(s)+2Fe^{3+}(aq)$

From this reaction we conclude that the electrons are getting transferred from iron to iodine and the number of electrons transferred are 6 electrons.

Hence, the correct option is, (C) 6

5 0

2 years ago