Energy released from cell respiration is know as

How will temperature affect the spontaneity of a reaction with positive H and S?

BartSMP [9]

Answer:

D.A high temperature will make it spontaneous.

Explanation:

we know that

Δ G = Δ H - TΔS

For spontaneous reaction

Δ G should be negative . If Δ G = 0

Δ H = TΔS

T = Δ H / Δ S

At temperature above this T , Δ G becomes negative if Δ S and ΔH are positive .

So at a high temperature will make it spontaneous.

5 0

3 years ago

How many coulombs are required to plate a layer of chromium metal 0.28 mm thick on an auto bumper with a total area of 0.40 m2 f

Rufina [12.5K]

Explanation:

The given data is as follows.

Thickness = 0.28 mm = $0.28 \times \frac{1}{10}$ cm = 0.028 cm

Area = 0.40 $m^{2}$ = $0.40 \times 10^{4} cm^{2}$ = 4000 $cm^{2}$

As, it is known that volume = area × thickness

So, Volume = $4000 cm^{2} \times 0.028 cm$

= 112 $cm^{3}$

As density is mass divided by volume. So, mass of chromium will be calculated as follows.

Density = $\frac{mass}{volume}$

7.20 $g/cm^{3}$ = $\frac{mass}{112 cm^{3}}$

mass = 806.4 g

As, mass of 1 mole of chromium is 52 g. So, number of moles in 806.4 g of chromium will be as follows.

No. of moles = $\frac{mass}{molar mass}$

= $\frac{806.4 g}{52 g}$

= 15.50 mol

In chromate ion, ( $CrO^{2-}_{4}$ ) charge on Cr is +6. It means that 6 electrons are needed to reduce $Cr^{+6}$ into Cr.

As, 1 mole of $Cr^{+6}$ ions require 6 moles of electrons. Therefore, moles of electrons for 15.50 mol will be calculated as follows.

6 × 15.50 mol = 93.04 mol

To calculate number of electrons we multiply number of moles by Avogadro's number as follows.

$93.04 mol \times 6.02 \times 10^{23}$

= $560.13 \times 10^{23}$

= $5.6 \times 10^{25}$ electrons

There is magnitude of $6.241 \times 10^{18}$ times the charge on an electron is equal to 1 coulomb.

Hence, number of coulombs will be as follows.

No. of coulombs = $\frac{5.6 \times 10^{25}}{6.241 \times 10^{18}}$

= $0.897 \times 10^{7}$ C

or, = $8.97 \times 10^{6}$ C

Thus, we can conclude that $8.97 \times 10^{6}$ C are required to plate a layer of chromium metal with given data.

4 0

3 years ago

A mixture of three gases has a pressure at 298 K of 1380 mm Hg. The mixture is analysed and is found to contain 1.27 mol CO2, 3.

enot [183]

Answer:

The partial pressure of Ar is 356.04 mm Hg (= 0.4685 atm)

Explanation:

Step 1: Data given

A mixture of three gases has a total pressure of 1380 mm Hg (=1.81579 atm) at 298 K

Moles of CO2 = 1.27 moles

Moles of CO = 3.04 moles

Moles of Ar = 1.50 moles

Step 2: Calculate total number of moles

Total number of moles = n(CO2)+ n(CO)+ n(Ar) = 1.27 mol+ 3.04 mol+ 1.50 mol = 5.81 moles

Step 3: Calculate mol fraction Ar

Mol fraction Ar = 1.50 mol/5.81 mol = 0.258

Step 4: Calculate partial pressure

1380 mm Hg * 0.258 moles Ar = 356.04 mm Hg = 0.4685 atm

The partial pressure of Ar is 356.04 mm Hg (= 0.4685 atm)

8 0

3 years ago

What is 251 in scientific notation

mel-nik [20]

It is 2.51×10 to the power of 2

8 0

3 years ago

Hi um whats a single and double reaction

abruzzese [7]

A single-replacement reaction is a chemical reaction in which one element is substituted for another element in a compound, generating a new element and a new compound as products.

A double-replacement reaction occurs when parts of two ionic compounds are exchanged, making two new compounds. A characteristic of a double-replacement equation is that there are two compounds as reactants and two different compounds as products.

The key difference between single displacement and double displacement reaction is that, in single displacement reactions, one chemical species replaces a part of another chemical species whereas, in double displacement reactions, exchange of two ionic species between two molecules occur.

Hope this helps you.

3 0

3 years ago