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3 years ago

15.

1 answer:

5 0

C.

Because the spinal cord functions primarily in the transmission of neural signals between the brain and the rest of the body

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If earth did not rotate what would happen to the global winds and why?

Anna35 [415]

If earth didn't rotate the global winds would stay on the same speed of rate because the wind isn't moving without rotation in the earths axis.

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3 years ago

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Thermochemistry

max2010maxim [7]

THe Answer is 105 J

hope this helps and please brainliest, I was first :)

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3 years ago

The free energy change for the following reaction at 25 °C, when [Cr3+] = 1.32×10-3 M and [Fe3+] = 1.14 M, is 131 kJ: Cr3+(1.32×

larisa [96]

Answer:

E°cell = - 1.3575 V

This reaction is spontaneous in the reverse direction

Explanation:

The given cell reaction:

Cr³⁺(1.32 × 10⁻³ M) + Fe²⁺(aq) → Cr²⁺(aq) + Fe³⁺(1.14 M)

The given Gibbs free energy: ΔG = 131 kJ = 131 × 10³ J (∵ 1 kJ = 10³ J)

As we know,

ΔG = - n F E°cell

Here, n - the number of moles of electrons transferred = 1

F - Faraday constant = 96500

E°cell - cell potential = ?

$\therefore E^{\circ }_{cell} = -\frac{\Delta G}{n \: F} = -\frac{131\times 10^{3}\, J}{1\, mol\times96500 \, C.mol^{-1}}$

$\Rightarrow E^{\circ }_{cell} = -1.3575\, V$

For a given chemical reaction if-

1. ΔG = negative and E°cell = positive

⇒ The reaction is spontaneous and proceeds spontaneously in the forward direction.

2. ΔG = positive and E°cell = negative

⇒ The reaction is non-spontaneous and proceeds spontaneously in the reverse direction.

Since, for this chemical reaction: 

Cr³⁺(1.32 × 10⁻³ M) + Fe²⁺(aq) → Cr²⁺(aq) + Fe³⁺(1.14 M)

ΔG = + 131 × 10³ J ⇒ positive

and, E°cell = - 1.3575 V ⇒ negative

Therefore, this reaction is spontaneous in the reverse direction.

6 0

3 years ago

A) Calculate the osmotic pressure difference between seawater and fresh water. For simplicity, assume thatall the dissolved salt

never [62]

Answer:

a) Δπ = 1.264 atm

b) W = 128 joules

c) ΔH >> W ( a factor greater than 17,000 )

Explanation:

a) The osmotic pressure, π , is determined by :

π = nRT/V, where n= moles of solute

R= 0.0821 Latm/kmol

T = 300 K

calling π(sw) osmotic pressure for for sea water and π (fw) for fresh water,

salinity of sea water = 3.5 g / 1L water (assuming only NaCl for the salts)

salinity of fresh water = 0.5 parts per thousand (range: 0- 0.5 ppt)

πsw = (3.5 g/58.44 g/mol) (0.0821 Latm/Kmol) (300 K ) /1 L = 1.475 atm

πfw = (0.5 g/58.44 g/mol) (0.0821 Latm/Kmol) (300 K ) /1 L = 0.211 atm

d water = 1 g/cm³

Δ π = (1.475 - 0.211) = 1.264 atm

b) W = Δπ V = 1.426 atm x 1L = 1.43 L-atm

1 L-atm = 101.33 j

W = 101.33 j/ Latm x 1.43 Latm = 128 joules

c) ΔH = Q₁ + nΔH vap, where

Q₁ = heat required to bring the solution from 300 K to boiling, 373 K

ΔH vap = heat of vaporization

Q = mCΔT = 1000 g x 4.186 j x 73 K = 305.6 j = 0.3056 kj

ΔH vap = (1000 g/ 18 g/mol ) 40.7 kj/mol = 2,261 kj

ΔH = 0.3056 kj + 2,261 kj = 2,261.3 kj

Note = Q << ΔH vap and we could have neglected it.

This result shows why nobody talks about evaporation of sea water to produce fresh water ΔH >> W

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3 years ago

Which of these is a chemical property?

ankoles [38]

Answer:

The second choice, or flammability.

Explanation:

The flammability of something is how easy it is for it to burn or ignite.

7 0

3 years ago

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